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Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Atomic-scale dynamics inside living cells explored by neutron scattering  

Science Journals Connector (OSTI)

...inside living cells explored by neutron scattering Marion Jasnin * * jasnin...specific usefulness of the neutron scattering technique to get insight into...cell types and organelles. neutron scattering|living cell|molecular dynamics...

2009-01-01T23:59:59.000Z

2

E-Print Network 3.0 - arc dynamic behavior Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Sample search results for: arc dynamic behavior Page: << < 1 2 3 4 5 > >> 1 GIS by ESRITM What is ArcGIS Summary: and events Dynamic segmentation Importing ArcView GIS...

3

Molecular dynamics simulation comparison of atomic scale intermixing at the amorphous Al2O3/semiconductor interface for a-Al2O3/Ge, a-Al2O3/InGaAs,  

E-Print Network [OSTI]

Molecular dynamics simulation comparison of atomic scale intermixing at the amorphous Al2O3/semiconductor interface for a-Al2O3/Ge, a-Al2O3/InGaAs, and a-Al2O3/InAlAs/InGaAs Evgueni A. Chagarov *, Andrew oxides Ge InGaAs InAlAs Oxide­semiconductor stack High-K oxide a b s t r a c t The structural properties

Kummel, Andrew C.

4

Simulations of Kinetic Events at the Atomic Scale  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of kinetic events at the atomic scale of kinetic events at the atomic scale Graeme Henkelman UT Austin Al / Al(100) B 3 I / Si Pd / MgO How can we simulate the dynamics of molecular systems over experimental time scales? Objective: To calculate dynamics of a surface over time scales which are much longer than can be calculated with direct classical dynamics. Problem: time scale gap fs ps ns ms ms s mins atomic dynamics thermally activated experimental vibrations simulations reaction dynamics time scales Most interesting transitions are rare 0.5 eV 1000/s events (much slower than vibrations) Simulating a transition for a typical rare event with classical dynamics can require ~10 12 force evaluations Transition state theory A statistical theory for calculating the rate of slow thermal processes

5

Dynamic voltage-current characteristics for a water jet plasma arc  

SciTech Connect (OSTI)

A virtual instrument technology is used to measure arc current, arc voltage, dynamic V-I characteristics, and nonlinear conductance for a cone-shaped water jet plasma arc under ac voltage. Experimental results show that ac arc discharge mainly happens in water vapor evaporated from water when heated. However, due to water's cooling effect and its conductance, arc conductance, reignition voltage, extinguish voltage, and current zero time are very different from those for ac arc discharge in gas work fluid. These can be valuable to further studies on mechanism and characteristics of plasma ac discharge in water, and even in gas work fluid.

Yang Jiaxiang; Lan Sheng; Xu Zuoming [College of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin, Heilongjiang 150040 (China)

2008-05-05T23:59:59.000Z

6

Atomic-Scale Simulations of Cascade Overlap and Damage Evolution...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide. Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide. Abstract:...

7

Structural materials: understanding atomic scale microstructures  

SciTech Connect (OSTI)

With the ability to locate and identify atoms in three dimensions, atom-probe tomography (APT) has revolutionized our understanding of structure-property relationships in materials used for structural applications. The atomic-scale details of clusters, second phases, and microstructural defects that control alloy properties have been investigated, providing an unprecedented level of detail on the origins of aging behavior, strength, creep, fracture toughness, corrosion, and irradiation resistance. Moreover, atomic-scale microscopy combined with atomistic simulation and theoretical modeling of material behavior can guide new alloy design. In this article, selected examples highlight how APT has led to a deeper understanding of materials structures and therefore properties, starting with the phase transformations controlling the aging and strengthening behavior of complex Al-, Fe-, and Ni-based alloys systems. The chemistry of interfaces and structural defects that play a crucial role in high-temperature strengthening, fracture, and corrosion resistance are also discussed, with particular reference to Zr- and Al-alloys and FeAl intermetallics.

Marquis, E A [University of Oxford; Miller, Michael K [ORNL; Blavette, D [Universite de Rouen, France; Ringer, S. P. [University of Sydney, Australia; Sudbrack, C [Northwestern University, Evanston; Smith, G.D.W. [University of Oxford

2009-01-01T23:59:59.000Z

8

Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.  

SciTech Connect (OSTI)

Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

2011-06-01T23:59:59.000Z

9

Simulations of Kinetic Events at the Atomic Scale  

Broader source: Energy.gov [DOE]

Presentation on the Simulations of Kinetic Events at the Atomic Scale given at the DOE Theory Focus Session on Hydrogen Storage Materials on May 18, 2006.

10

Discovery of novel hydrogen storage materials: an atomic scale...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Discovery of novel hydrogen storage materials: an atomic scale computational approach Home Author: C. Wolverton, D. J. Siegel, A. R. Akbarzadeh, V. Ozolins Year: 2008 Abstract:...

11

Effects of Atomic Scale Roughness at Metal/insulator Interfaces...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Work Function. Effects of Atomic Scale Roughness at Metalinsulator Interfaces on Metal Work Function. Abstract: We evaluate the performance of different van der Waals (vdW)...

12

Argonne CNM Highlight: Atomic Scale Modeling and Simulation of Silicon  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Atomic Scale Modeling and Simulation of Silicon Anisotropic Etching Atomic Scale Modeling and Simulation of Silicon Anisotropic Etching N. Moldovan A well-known process in microelectromechanical systems (MEMS) technology involves etching silicon in alkaline solutions, which produces accurate 3-D silicon structures, sometimes with atomic smoothness, by taking advantage of the strong dependence of the etching rate on crystal orientation. Significant experimental effort has been made to characterize this anisotropy (polar etching rate diagrams, temperature dependencies, roughness measurements, in situ STM records during etching, electrochemistry studies etc.). The experimental results were used in complex simulations that successfully predicted the evolution of the 3-D geometry, starting from the experimentally measured etching diagrams.

13

High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs  

DOE Patents [OSTI]

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

Shimer, D.W.; Lange, A.C.

1995-05-23T23:59:59.000Z

14

High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs  

DOE Patents [OSTI]

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1995-01-01T23:59:59.000Z

15

E-Print Network 3.0 - arc welding dynamic Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a system IO board; arc sensor interface board for weld seam tracking... inverter power source renders possible ... Source: Ang Jr.,, Marcelo H. - Department of Mechanical...

16

Atomic-scale design of radiation-tolerant nanocomposites  

SciTech Connect (OSTI)

Recent work indicates that materials with nanoscale architectures, such as nanolayered Cu-Nb composites and nanoscale oxide dispersion-strengthened steels, are both thermally stable and offer improved performance under irradiation. Current understanding of the atomic-level response of such materials to radiation yields insights into how controlling composition, morphology, and interface-defect interactions may further enable atomic-scale design of radiation-tolerant nanostructured composite materials. With greater understanding of irradiation-assisted degradation mechanisms, this bottom-up design approach may pave the way for creating the extreme environment—tolerant structural materials needed to meet the world's clean energy demand by expanding use of advanced fission and future fusion power.

Demkowicz, M J; Bellon, P; Wirth, B D

2010-01-01T23:59:59.000Z

17

Effects of Stone-Wales and vacancy defects in atomic-scale friction on defective graphite  

SciTech Connect (OSTI)

Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite.

Sun, Xiao-Yu [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China); Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Wu, RunNi; Xia, Re [Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Chu, Xi-Hua; Xu, Yuan-Jie, E-mail: yj-xu@whu.edu.cn [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China)

2014-05-05T23:59:59.000Z

18

Direct atomic-scale observation of layer-by-layer oxide growth during magnesium oxidation  

SciTech Connect (OSTI)

The atomic-scale oxide growth dynamics are directly revealed by in situ high resolution transmission electron microscopy during the oxidation of Mg surface. The oxidation process is characterized by the layer-by-layer growth of magnesium oxide (MgO) nanocrystal via the adatom process. Consistently, the nucleated MgO crystals exhibit faceted surface morphology as enclosed by (200) lattice planes. It is believed that the relatively lower surface energies of (200) lattice planes should play important roles, governing the growth mechanism. These results facilitate the understanding of the nanoscale oxide growth mechanism that will have an important impact on the development of magnesium or magnesium alloys with improved resistance to oxidation.

Zheng, He; Wu, Shujing; Sheng, Huaping; Liu, Chun; Liu, Yu; Cao, Fan; Zhou, Zhichao; Zhao, Dongshan, E-mail: wang@whu.edu.cn, E-mail: dszhao@whu.edu.cn; Wang, Jianbo, E-mail: wang@whu.edu.cn, E-mail: dszhao@whu.edu.cn [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072 (China); Zhao, Xingzhong [School of Physics and Technology, Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan 430072 (China)

2014-04-07T23:59:59.000Z

19

E-Print Network 3.0 - atomic-scale contact potential Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Energy Storage, Conversion and Utilization ; Renewable Energy 6 Detection of Heavy Metal Ions Based on Quantum Point Contacts Summary: separated by atomic scale gaps. By...

20

E-Print Network 3.0 - atomic scale analysis Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

determine the atomic-scale structure of nanocrystals in detail... -energy XRD and atomic PDF ... Source: Petkov, Valeri - Department of Physics, Central Michigan University...

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

E-Print Network 3.0 - atomic scale structure Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic scale structure Page: << < 1 2 3 4 5 > >> 1 Extended Xray Absorption Fine Structure...

22

Adhesion, Lubrication, and Wear on the Atomic Scale James B. Adams  

E-Print Network [OSTI]

Adhesion, Lubrication, and Wear on the Atomic Scale James B. Adams Dept. of Chemical and Materials, lubrication and wear) of tribology on the atomic Scale with a focus on our group's work on Aluminum. Adhesion to control friction and wear in bulk metal processes, lubricant boundary additives are added to bind

Adams, James B

23

Atomic-scale electron-beam sculpting of defect-free graphene nanostructures  

E-Print Network [OSTI]

Atomic-scale electron-beam sculpting of defect-free graphene nanostructures Bo Song, Grégory F.w.zandbergen@tudelft.nl ABSTRACT. In order to harvest the many promising properties of graphene in (electronic) applications a temperature-dependent self-repair mechanism allowing damage-free atomic-scale sculpting of graphene using

Dekker, Cees

24

Atomic-Scale Chemical Imaging via Combination of Scanning Tunneling and Electron Energy Loss Spectroscopies  

E-Print Network [OSTI]

systems at atomic level Develop atomically resolved chemical imaging platform via combination of lowAtomic-Scale Chemical Imaging via Combination of Scanning Tunneling and Electron Energy Loss visualization of chemical reaction pathways to provide mechanistic understanding for catalytically important

25

Atomic-Scale Imaging and Spectroscopy for In Situ Liquid Scanning Transmission Electron Microscopy  

SciTech Connect (OSTI)

Observation of growth, synthesis, dynamics and electrochemical reactions in the liquid state is an important yet largely unstudied aspect of nanotechnology. The only techniques that can potentially provide the insights necessary to advance our understanding of these mechanisms is simultaneous atomic-scale imaging and quantitative chemical analysis (through spectroscopy) under environmental conditions in the transmission electron microscope (TEM). In this study we describe the experimental and technical conditions necessary to obtain electron energy loss (EEL) spectra from a nanoparticle in colloidal suspension using aberration corrected scanning transmission electron microscopy (STEM) combined with the environmental liquid stage. At a fluid path length below 400 nm, atomic resolution images can be obtained and simultaneous compositional analysis can be achieved. We show that EEL spectroscopy can be used to quantify the total fluid path length around the nanoparticle, and demonstrate characteristic core-loss signals from the suspended nanoparticles can be resolved and analyzed to provide information on the local interfacial chemistry with the surrounding environment. The combined approach using aberration corrected STEM and EEL spectra with the in situ fluid stage demonstrates a plenary platform for detailed investigations of solution based catalysis and biological research.

Jungjohann, K. L.; Evans, James E.; Aguiar, Jeff; Arslan, Ilke; Browning, Nigel D.

2012-06-04T23:59:59.000Z

26

Atomic-Scale Observation of Temperature and Pressure Driven Preroughening and Roughening  

E-Print Network [OSTI]

Atomic-Scale Observation of Temperature and Pressure Driven Preroughening and Roughening Z. Ding, D, Oklahoma 73019, USA (Received 13 January 2003; published 30 May 2003) Preroughening and roughening is roughening [6,7]. Here it is common for the surface morphology to change from a flat surface directly to one

Thibado, Paul M.

27

An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes  

E-Print Network [OSTI]

An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes M Growth of carbon nanotubes during transition-metal particles catalytically-assisted thermal decomposition of various nanotube surface and edge reactions (e.g. adsorption of hydrocarbons and hydrogen onto the surface

Grujicic, Mica

28

Atomic-Scale Mapping of Thermoelectric Power on Graphene: Role of Defects and Boundaries  

E-Print Network [OSTI]

by conductance measurements alone. Indeed, the thermoelectric properties of this two-dimensional material have scattering effects in thermoelectric materials. An alternative way to study the thermoelectric properties1 Atomic-Scale Mapping of Thermoelectric Power on Graphene: Role of Defects and Boundaries Jewook

Feenstra, Randall

29

Electronic Heating at High Bias in Atomic-Scale Au Break Junctions Ruoyu Chen,1  

E-Print Network [OSTI]

, U.S.A. Heating in nanoscale systems driven out of equilibrium is of fundamental importance, has O-10 Electronic Heating at High Bias in Atomic-Scale Au Break Junctions Ruoyu Chen,1, Texas, U.S.A. 2 Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005

30

Atomic-Scale Detection of Organic Molecules Coupled to Single-Walled Carbon Nanotubes  

E-Print Network [OSTI]

Atomic-Scale Detection of Organic Molecules Coupled to Single-Walled Carbon Nanotubes Sung You Hong.green@chem.ox.ac.uk; ben.davis@chem.ox.ac.uk Functionalized carbon nanotubes (f-CNTs) bearing organic molecules functionalization of single-walled carbon nanotubes (SWNTs) can tailor critical proper- ties such as solubility

Davis, Ben G.

31

Vacancy clustering in zirconium: an atomic scale study$ Celine Varvenne1  

E-Print Network [OSTI]

Vacancy clustering in zirconium: an atomic scale study$ C´eline Varvenne1 , Olivier Mackain Abstract The stability properties of vacancy clusters in hexagonal close-packed Zr, cavities theory and empirical potentials. Considering the vacancy-vacancy interactions and the stability of small

Paris-Sud XI, Université de

32

Implementation and evaluation of modified dynamic conformal arc (MDCA) technique for lung SBRT patients following RTOG protocols  

SciTech Connect (OSTI)

To implement modified dynamic conformal arc (MDCA) technique and Radiation Therapy Oncology Group (RTOG) protocols in our clinic for stereotactic body radiation therapy (SBRT) treatment of patients with Stage I/II non–small cell lung cancer. Five patients with non–small cell lung cancer have been treated with SBRT. All the patients were immobilized using CIVCO Body Pro-Lok system and scanned using GE 4-slice computed tomography. The MDCA technique that was previously published was adopted as our planning technique, and RTOG protocols for the lung SBRT were followed. The patients were treated on Novalis Tx system with cone-beam computed tomography imaging guidance. All the patient plans passed the RTOG criteria. The conformal index ranges from 0.99 to 1.12 for the planning target volume, and the biological equivalent dose for the planning target volume is overall 100 Gy. Critical structures (lung, spinal cord, brachial plexus, skin, and chest wall) also meet RTOG protocols or published data. A 6-month follow-up of one of the patients shows good local disease control. We have successfully implemented the MDCA technique into our clinic for the lung SBRT program. It shows that the MDCA is useful and efficient for the lung SBRT planning, with the plan quality meeting the RTOG protocols.

Shi, Chengyu, E-mail: shicy1974@gmail.com [St. Vincent's Medical Center, Bridgeport, CT (United States); Tazi, Adam; Fang, Deborah Xiangdong; Iannuzzi, Christopher [St. Vincent's Medical Center, Bridgeport, CT (United States)

2013-10-01T23:59:59.000Z

33

Creating a Precise Atomic-Scale Map of Quantum Dots | Advanced Photon  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Getting to the Roots of Lethal Hairs Getting to the Roots of Lethal Hairs Stressing Out the Twins in Magnesium Size-Related Behavior of Anatase Nanocrystals under Extreme Pressure Boron-Based Compounds Trick a Biomedical Protein A Targeted Cancer Treatment using Nanomaterials Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Creating a Precise Atomic-Scale Map of Quantum Dots OCTOBER 9, 2009 Bookmark and Share An atomic-scale map of the interface between an atomic dot and its substrate. Each peak represents a single atom. The map, made with high-intensity x-rays at the APS, is a slice through a vertical cross-section of the dot. (Image courtesy of Roy Clarke, University of

34

3-D Atomic-Scale Mapping of Manganese Dopants in Lead Sulfide Nanowires  

SciTech Connect (OSTI)

Dopants in nanowires, whether intentional or unintentional, can ultimately control the material's properties and therefore need to be understood on the atomic scale. We study vapor-liquid-solid grown manganese-doped lead sulfide nanowires by atom-probe tomography for the first time for lead salt materials. The three-dimensional chemical concentration maps at the atomic scale demonstrate a radial distribution profile of Mn ions, with a concentration of only 0.18 at.% and 0.01 at.% for MnCl2 and Mn-acetate precursors, respectively. The ability to characterize these small concentrations of dopant atoms in Pb1-xMnxS nanowires (x = 0.0036 and 0.0002), important for spintronic and thermoelectric devices, sets a platform for similar analyses for all nanostructures. First-principles calculations confirm that Mn atoms substitute for Pb in the PbS structure.

Isheim, Dieter; Kaszpurenko, Jason; Yu, Dong; Mao, Zugang; Seidman, David N.; Arslan, Ilke

2012-03-22T23:59:59.000Z

35

Anode and Cathode Arcs  

Science Journals Connector (OSTI)

... we call an anode arc, produces a circular pit on the anode and a general roughening of the opposed cathode. Photomicrographs of single anode-type arcs were published1 before the ... arcs\tCathode arcs

L. H. GERMER; W. S. BOYLE

1955-11-26T23:59:59.000Z

36

Atomic-Scale Engineering of the SiC-SiO{sub 2} Interface  

SciTech Connect (OSTI)

We report results from three distinct but related thrusts that aim to elucidate the atomic-scale structure and properties of the Sic-SiO{sub 2} interface. (a) First-principles theoretical calculations probe the global bonding arrangements and the local processes during oxidation; (b) Z-contrast atomic-resolution transmission electron microscopy and electron-energy-loss spectroscopy provide images and interface spectra, and (c) nuclear techniques and electrical measurements are used to profile N at the interface and determine interface trap densities.

Buczko, R.; Chung, G.; Di Ventra, M.; Duscher, G.; Feldman, L.C.; Huang, M.B.; McDonald, K.; Pantelides, S.T.; Pennycook, S.J.; Radtke, C.; Stedile, F.C.; Tin, C.C.; Weller, R.A. Baumvol, I.; Williams, J.R.; Won, J.

1999-11-14T23:59:59.000Z

37

Atomic-scale chemical quantification of oxide interfaces using energy-dispersive X-ray spectroscopy  

SciTech Connect (OSTI)

Atomic-scale quantification of chemical composition across oxide interfaces is important for understanding physical properties of epitaxial oxide nanostructures. Energy-dispersive X-ray spectroscopy (EDS) in an aberration-corrected scanning transmission electron microscope was used to quantify chemical composition across the interface of ferromagnetic La{sub 0.7}Sr{sub 0.3}MnO{sub 3} and antiferromagnetic BiFeO{sub 3} quantum structure. This research demonstrates that chemical composition at atomic columns can be quantified by Gaussian peak-fitting of EDS compositional profiles across the interface. Cation diffusion was observed at both A- and B-sublattice sites; and asymmetric chemical profiles exist across the interface, consistent with the previous studies.

Lu, Ping; Van Benthem, Mark [Sandia National Laboratories, P.O. Box 5800, MS 1411, Albuquerque, New Mexico 87185-1411 (United States)] [Sandia National Laboratories, P.O. Box 5800, MS 1411, Albuquerque, New Mexico 87185-1411 (United States); Xiong, Jie; Jia, Quanxi [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-04-29T23:59:59.000Z

38

Fabrication of atomic-scale gold junctions by electrochemical plating using a common medical liquid  

Science Journals Connector (OSTI)

Fabrication of nanometer-separated gold junctions has been performed using “iodine tincture ” a medical liquid known as a disinfectant as an etching/deposition electrolyte. In the gold-dissolved iodine tincture goldelectrodes were grown or eroded slowly enough to form quantum point contacts in an atomic scale. The resistance evolution during the electrochemicaldeposition showed plateaus at integer multiples of the resistance quantum ( 2 e 2 ? h ) ? 1 at room temperature ( e : the elementary charge h : the Planck constant). Iodine tincture is a commercially available common material which makes the fabrication process to be simple and cost effective. Moreover in contrast to the conventional electrochemical approaches this method is free from highly toxic cyanide compounds or extraordinarily strong acids.

A. Umeno; K. Hirakawa

2005-01-01T23:59:59.000Z

39

PROCEDURES FOR ARC PROJECTS  

E-Print Network [OSTI]

PROCEDURES FOR ARC PROJECTS Revised - May 2013 Agricultural Research Center Washington State University #12;Table of Contents THE PROJECT SYSTEM, AN INTRODUCTION................................................................................. 5 DEVELOPING AN ARC PROJECT

Collins, Gary S.

40

Method for large-scale fabrication of atomic-scale structures on material surfaces using surface vacancies  

DOE Patents [OSTI]

A method for forming atomic-scale structures on a surface of a substrate on a large-scale includes creating a predetermined amount of surface vacancies on the surface of the substrate by removing an amount of atoms on the surface of the material corresponding to the predetermined amount of the surface vacancies. Once the surface vacancies have been created, atoms of a desired structure material are deposited on the surface of the substrate to enable the surface vacancies and the atoms of the structure material to interact. The interaction causes the atoms of the structure material to form the atomic-scale structures.

Lim, Chong Wee (Urbana, IL); Ohmori, Kenji (Urbana, IL); Petrov, Ivan Georgiev (Champaign, IL); Greene, Joseph E. (Champaign, IL)

2004-07-13T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Effect of atomic scale plasticity on hydrogen diffusion in iron: Quantum mechanically informed and on-the-fly kinetic  

E-Print Network [OSTI]

viewpoints, is futile. Among several mechanisms proposed for hydrogen embrittlement (HE) of metals, hydrogenEffect of atomic scale plasticity on hydrogen diffusion in iron: Quantum mechanically informed-assisted diffusion and trapping of hydrogen by crystalline defects in iron. Given an embedded atom (EAM) potential

Ortiz, Michael

42

Unipolar arc simulation device  

SciTech Connect (OSTI)

We describe a simple laboratory device for establishing a vacuum arc plasma discharge that can serve to simulate a unipolar arc. The technique makes use of a triggered vacuum arc plasma gun to generate a plasma plume that in turn causes breakdown of a secondary discharge. The device is in fact a secondary vacuum arc discharge that is triggered by a primary vacuum arc discharge, with some of the features of the secondary plasma discharge having similarities with a unipolar arc configuration. Here we describe the experimental setup and outline how the device can be used for some areas of unipolar arc materials research. [copyright] [ital 1999 American Institute of Physics.

Wang, S.G.; Brown, I.G. (Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States))

1999-09-01T23:59:59.000Z

43

Atomic-scale X-ray structural analysis of self-assembled monolayers on Silicon  

SciTech Connect (OSTI)

Two related self-assembled monolayers (SAMs), 4-bromostyrene (BrSty) and 4-bromophenylacetylene (BPA), are photochemically grown from solution on to the monohydride-terminated Si(111) surface. The atomic-scale structures of the resulting SAMs are examined by X-ray standing waves (XSW), X-ray reflectivity (XRR), X-ray fluorescence, atomic-force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The coverage is 0.5 ML. The results show that in each case the molecule covalently bonds to a single Si T{sub 1} site and stands up-right with a slight molecular tilt of 17{sup o} that leaves the Br terminal end over a neighboring T{sub 4} site. The Br height is 8.5 {angstrom} (BrSty) and 8.6 {angstrom} (BPA) above the top surface Si atom. The combined XSW and XRR results rule-out two alternative bonding models predicted by DFT that have the root of the molecule bonded to two neighboring top Si surface atoms. Based on the XSW 111 and 333 coherent fractions, the BPA/Si(111) has a reduced vertical Br distribution width in comparison to BrSty. This greater rigidity in the molecular structure is correlated to a C=C bond at the root.

Lin, J.-C.; Kellar, J.A.; Kim, J.-H.; Yoder, N.L.; Bevan, K.H.; Nguyen, S.T.; Hersam, M.C.; Bedzyk, M.J.; (NWU); (Purdue)

2009-04-02T23:59:59.000Z

44

C. Tavakoli et al.: Dynamics and Modeling of AC Arc on Surface of Ice 1070-9878/06/$20.00 2006 IEEE  

E-Print Network [OSTI]

discharge activities leading to flashover on ice-covered insulator surface is presented. This model takes modeling, arc modeling, outdoor insulation, atmospheric icing. 1 INTRODUCTION OVERHEAD power lines icing deposited on insulators. The study and understanding of arc initiation and propagation

Paris-Sud XI, Université de

45

Rates of tectonic and magmatic processes in the North Cascades continental magmatic arc  

E-Print Network [OSTI]

Continental magmatic arcs are among the most dynamic. geologic systems, and documentation of the magmatic, thermal, and tectonic evolution of arcs is essential for understanding the processes of magma generation, ascent ...

Matzel, Jennifer E. Piontek, 1973-

2004-01-01T23:59:59.000Z

46

Numerical modeling of the interaction between an electric arc and a gas flow  

Science Journals Connector (OSTI)

The interaction between an equilibrium arc discharge and a gas (air or argon) ... The dynamics and the special features of the electric arc formation are studied for both gases. In the air the electrically conduc...

E. N. Vasil’ev; D. A. Nesterov

2013-03-01T23:59:59.000Z

47

Sliding electric arc discharge as a means of aircraft trajectory control  

Science Journals Connector (OSTI)

The dynamics of sliding electric arc discharge and the formation of shock waves in the stages of leader motion and the electric arc development in a supersonic air flow behind ... (bar). The air flow in the discharge

V. S. Aksenov; V. V. Golub; S. A. Gubin; V. P. Efremov…

2004-10-01T23:59:59.000Z

48

Atomic scale 0-pi transition in a high-Tc superconductor/ferromagnetic-insulator/high-T superconductor Josephson junction  

E-Print Network [OSTI]

We study the Josephson transport in a high-Tc superconductor/ferromagnetic-insulator(FI)/high-Tc superconductor numerically. We found the formation of a pi-junction in such systems. More remarkably the ground state of such junction alternates between 0- and pi-states when thickness of FI is increasing by a single atomic layer. We propose an experimental setup for observing the atomic-scale 0-pi transition. Such FI-based pi-junctions can be used to implement highly-coherent quantum bits.

Kawabata, Shiro; Asano, Yasuhiro

2011-01-01T23:59:59.000Z

49

Taupo's atypical arc  

Science Journals Connector (OSTI)

... many other continental arcs around the world, with andesite-dacite cone volcaaoes and relatively low geothermal heat fluxes. In sharp contrast, in the middle

Colin J. N. Wilson

1996-01-04T23:59:59.000Z

50

Cathodic Arc Plasma Deposition  

Office of Scientific and Technical Information (OSTI)

Cathodic Arc Plasma Deposition Cathodic Arc Plasma Deposition André Anders Lawrence Berkeley National Laboratory, University of California, 1 Cyclotron Road, Mailstop 53, Berkeley, California 94720 aanders@lbl.gov Abstract Cathodic arc plasma deposition is one of oldest coatings technologies. Over the last two decades it has become the technology of choice for hard, wear resistant coatings on cutting and forming tools, corrosion resistant and decorative coatings on door knobs, shower heads, jewelry, and many other substrates. The history, basic physics of cathodic arc operation, the infamous macroparticle problem and common filter solutions are reviewed. Cathodic arc plasmas stand out due to their high degree of ionization, with important consequences for film nucleation, growth, and efficient utilization of substrate bias. The

51

Electric arc saw apparatus  

DOE Patents [OSTI]

A portable, hand held electric arc saw has a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc to erode a workpiece. Electric current is supplied to the blade by biased brushes and a slip ring which are mounted in the frame. A pair of freely movable endless belts in the form of crawler treads stretched between two pulleys are used to facilitate movement of the electric arc saw. The pulleys are formed of dielectric material to electrically insulate the crawler treads from the frame.

Deichelbohrer, Paul R [Richland, WA

1986-01-01T23:59:59.000Z

52

Welding arc initiator  

DOE Patents [OSTI]

An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome. 3 figs.

Correy, T.B.

1989-05-09T23:59:59.000Z

53

Welding arc initiator  

DOE Patents [OSTI]

An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome.

Correy, Thomas B. (Richland, WA)

1989-01-01T23:59:59.000Z

54

Formation of ion irradiation-induced atomic-scale defects on walls of carbon nanotubes A. V. Krasheninnikova b, K. Nordlundb, M. Sirviob, E. Salonenb and J. Keinonenb  

E-Print Network [OSTI]

of nanotubes with Ar ions. For this, we simulate impact events over a wide energy range of incident ions. WeFormation of ion irradiation-induced atomic-scale defects on walls of carbon nanotubes A. V carbon nanotubes provide evidence that ion bombardment gives rise to nan- otube amorphization

Nordlund, Kai

55

Vacuum arc deposition devices  

SciTech Connect (OSTI)

The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

Boxman, R.L.; Zhitomirsky, V.N. [Electrical Discharge and Plasma Laboratory, Faculty of Engineering, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978 (Israel)

2006-02-15T23:59:59.000Z

56

College of Design ARC Architecture  

E-Print Network [OSTI]

College of Design ARC Architecture KEY: # = new course * = course changed = course dropped,landscape,andarchitecturalspaceswithattentiontotheirapplicationtothearchitecturalexperience.Studio:4hoursperweek. Prereq: Admission to the School of Architecture. ARC 102 DRAWING II: OBSERVATIONAL OF ARCHITECTURE. (3

MacAdam, Keith

57

Hall-effect arc protector  

DOE Patents [OSTI]

The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored.

Rankin, Richard A. (Ammon, ID); Kotter, Dale K. (Shelley, ID)

1997-01-01T23:59:59.000Z

58

Hall-effect arc protector  

DOE Patents [OSTI]

The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored. 2 figs.

Rankin, R.A.; Kotter, D.K.

1997-05-13T23:59:59.000Z

59

Experimental evidence of chaotic behavior in atmospheric pressure arc discharge  

SciTech Connect (OSTI)

Thermal plasma technology is already playing an important role in the production of new materials, in the destruction of toxic wastes, and in the development of safer and more efficient manufacturing and material processing applications. In free burning as well as in stabilized arc columns, the inherent movement of arc root results in fluctuation in arc voltage. A full knowledge and control over the arc root dynamics can effectively lengthen the life time, drastically improve performance and reliability in arc plasma devices. In this paper, the authors experimentally investigate the fluctuating voltage signals generated from an atmospheric pressure arc discharge produced in a hollow electrode plasma torch. For the first time, analysis of these signals reveal them to exhibit chaotic behavior. The present analysis is supported with real time behavior, phase portraits, power spectra and Lyapunov exponents. Dependence of system behavior on various control parameters is also investigated. This approach is interesting in the sense that it can lead to better understanding of physics for future researches on arc plasma jets and related devices.

Ghorui, S.; Sahasrabudhe, S.N.; Murthy, P.S.S.; Das, A.K.; Venkatramani, N.

2000-02-01T23:59:59.000Z

60

GIS Fundamentals: Supplementary Lessons with ArcGIS Introduction to ArcGIS Lesson 1: Introduction to ArcGIS  

E-Print Network [OSTI]

GIS Fundamentals: Supplementary Lessons with ArcGIS Introduction to ArcGIS 1 Lesson 1: Introduction to ArcGIS What You'll Learn: -Start ArcMap -Create a new map -Add data layers -Pan and zoom -Change data errors. Background: This is the first in a series of introductory exercises for ArcGIS

Harbor, David

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Arc fault detection system  

DOE Patents [OSTI]

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

Jha, Kamal N. (Bethel Park, PA)

1999-01-01T23:59:59.000Z

62

Voltage flicker prediction for two simultaneously operated ac arc furnaces  

SciTech Connect (OSTI)

An EMTP-based arc furnace model was developed for evaluation of flicker concerns associated with supplying a large integrated steel mill as they go from one to two furnace operation and as system changes are implemented that will affect the short circuit capacity at the 230 kV power supply substation. The model includes a dynamic arc representation which is designed to be characteristic of the initial portions of the melt cycle when the arc characteristics are the most variable (worst flicker conditions). The flicker calculations are verified using previous measurements with one furnace operation. Flicker simulations were then performed to evaluate a variety of different possible system strengths with both one and two furnaces in operation. The primary flicker measure used for this study is the unweighted rms value of the fluctuation envelope, expressed as a percentage of the rms line-to-ground voltage magnitude.

Tang, L. [ABB Power T and D Co., Inc., Raleigh, NC (United States)] [ABB Power T and D Co., Inc., Raleigh, NC (United States); Kolluri, S. [Entergy Services, New Orleans, LA (United States)] [Entergy Services, New Orleans, LA (United States); McGranaghan, M.F. [Electrotek Concepts, Inc., Knoxville, TN (United States)] [Electrotek Concepts, Inc., Knoxville, TN (United States)

1997-04-01T23:59:59.000Z

63

Dynamic behaviour of electric arc gas discharge  

Science Journals Connector (OSTI)

The time-dependent energy and circuit equations are solved numerically to obtain temperature profiles, current-voltage characteristics and electric field strength vs axial temperature diagrams in the asymptoti...

J. Jeništa

1994-01-01T23:59:59.000Z

64

Confined plasma gliding arc discharges  

Science Journals Connector (OSTI)

A confined plasma gliding arc is produced in a reactor with two-electrodes contained within a very narrow channel and water spray injected into the discharge. The evolution of pH and conductivity and the formation of hydrogen peroxide in pure water with different carrier gases and the decolourisation and mineralisation of an organic dye were compared with results for a non-confined three-electrode gliding arc reactor. The energy efficiency for the decolourisation of an organic blue dye in the confined reactor is twice that of the non-confined reactor. Significant levels of total organic carbon are removed in the confined plasma reactor.

Radu Burlica; Bruce R. Locke

2008-01-01T23:59:59.000Z

65

MagLab - Arc Lamp Tutorial  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

with 2,000 cells to create an arc across a 4-inch (100 millimeter) gap. When suitable electric generators became available in the late 1870s, the practical use of arc lamps began....

66

Oxygen and Nitrogen Contamination During Arc Welding  

E-Print Network [OSTI]

) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, mechanisms, and expected levels of oxygen and nitrogen contamination during gas tungsten arc, gas metal arc indicating the importance of dec9mposition of SiOz into silicon monoxide and oxygen are presented, indicating

Eagar, Thomas W.

67

Direct Atomic-Scale Observation of Redox-Induced Cation Dynamics in an Oxide-Supported Monolayer Catalyst: WOx/r-Fe2O3(0001)  

E-Print Network [OSTI]

Catalyst: WOx/r-Fe2O3(0001) Zhenxing Feng, Chang-Yong Kim,§ Jeffrey W. Elam,| Qing Ma, Zhan Zhang catalysts for industrial processes.1 Typically, a catalyst exhibits greater activity as a monolayer (ML the structure of the catalyst affects chemical reactions, as, for example, in the proposed case

Mohseni, Hooman

68

Characterization of arcs in frequency domain  

SciTech Connect (OSTI)

Arc detection systems are developed for ICRH on ITER to prevent arcs from damaging the RF components. One of the detectors, the Sub-Harmonic Arc Detector (SHAD) is based on the detection of the frequencies emitted in the MHz range by arcs [R1]. To ensure the high level of reliability required for this safety system, it is necessary to demonstrate that these frequencies present a signal with a Signal to Noise Ratio high enough to be detected under the wide range of operational conditions (frequency, power, configuration) and for the different types of arcs that can appear in the feeding lines and on the antennas (vacuum arc, glow discharge, multipactor-induced discharge). For each type of arc, we analyze the evolution of the frequency spectrum relative to the evolution of other electrical parameters (reflected power, voltage)

D'Inca, R.; Siegl, G.; Faugel, H.; Braun, F.; Eckert, B.; Bobkov, V. [Max Planck Institut fuer Plasmaphysik, Garching, Germany, EURATOM Association (Germany); El Khaldi, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Noterdaeme, J.-M. [Max Planck Institut fuer Plasmaphysik, Garching, Germany, EURATOM Association (Germany); Gent University, EESA Department (Belgium)

2009-11-26T23:59:59.000Z

69

Filters for cathodic arc plasmas  

DOE Patents [OSTI]

Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA); Bilek, Marcela M. M. (Engadine, AU); Brown, Ian G. (Berkeley, CA)

2002-01-01T23:59:59.000Z

70

Catalyst Dynamics during Carbon Nanotube and Si Nanowire CVD S. Hofmann,*  

E-Print Network [OSTI]

Catalyst Dynamics during Carbon Nanotube and Si Nanowire CVD S. Hofmann,* R. Sharma,** R. Blume catalysts and specifically their interface dynamics. We present atomic-scale environmental transmission electron microscopy (ETEM) and in-situ X- ray photoelectron spectroscopy (XPS) of catalyst assisted growth

Dunin-Borkowski, Rafal E.

71

Characterization of an atmospheric double arc argon-nitrogen plasma source  

SciTech Connect (OSTI)

In the framework of studies devoted to hazardous waste destruction, an original dc double anode plasma torch has been designed and tested, which produces an elongated, weak fluctuation and reproducible plasma jet at atmospheric pressure. The arc instabilities and dynamic behavior of the double arc argon-nitrogen plasma jet are investigated through the oscillations of electrical signals by combined means of fast Fourier transform and Wigner distribution. In our experiment, the restrike mode is identified as the typical fluctuation behavior in an argon-nitrogen plasma jet. The Fourier spectra and Wigner distributions exhibit two characteristic frequencies of 150 Hz and 4.1 kHz, which reveals that the nature of fluctuations in the double arc argon-nitrogen plasma can be ascribed to the undulation of the power supply and both arc roots motion on the anode channels. In addition, the microscopic properties of the plasma jet inside and outside the arc chamber are investigated by means of optical emission spectroscopy, which yields excitation, electronic, rotational, and vibrational temperatures, as well as the electron number density. The results allow us to examine the validity criteria of a local thermodynamic equilibrium (LTE) state in the plasma arc. The measured electron densities are in good agreement with those calculated from the LTE model, which indicates that the atmospheric double arc argon-nitrogen plasma in the core region is close to the LTE state under our experimental conditions.

Tu, X. [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); UMR 6614 CNRS CORIA, Saint Etienne du Rouvray 76801 (France); Cheron, B. G. [UMR 6614 CNRS CORIA, Saint Etienne du Rouvray 76801 (France); Yan, J. H.; Yu, L.; Cen, K. F. [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China)

2008-05-15T23:59:59.000Z

72

True atomic-scale imaging of a spinel Li{sub 4}Ti{sub 5}O{sub 12}(111) surface in aqueous solution by frequency-modulation atomic force microscopy  

SciTech Connect (OSTI)

Spinel-type lithium titanium oxide (LTO; Li{sub 4}Ti{sub 5}O{sub 12}) is a negative electrode material for lithium-ion batteries. Revealing the atomic-scale surface structure of LTO in liquid is highly necessary to investigate its surface properties in practical environments. Here, we reveal an atomic-scale image of the LTO(111) surface in LiCl aqueous solution using frequency-modulation atomic force microscopy. Atomically flat terraces and single steps having heights of multiples of 0.5?nm were observed in the aqueous solution. Hexagonal bright spots separated by 0.6?nm were also observed on the flat terrace part, corresponding to the atomistic contrast observed in the ultrahigh vacuum condition, which suggests that the basic atomic structure of the LTO(111) surface is retained without dramatic reconstruction even in the aqueous solution.

Kitta, Mitsunori, E-mail: m-kitta@aist.go.jp; Kohyama, Masanori [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Onishi, Hiroshi [Department of Chemistry, Graduate School of Science, Kobe University 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

2014-09-15T23:59:59.000Z

73

Metals purification by improved vacuum arc remelting  

DOE Patents [OSTI]

The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

Zanner, Frank J. (Sandia Park, NM); Williamson, Rodney L. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

1994-12-13T23:59:59.000Z

74

Miniaturized cathodic arc plasma source  

DOE Patents [OSTI]

A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

2003-04-15T23:59:59.000Z

75

Plasma of Electric Arc Discharge between Melted Electrodes  

Science Journals Connector (OSTI)

Plasma of electric arc discharge between melted electrodes was experimentally investigated. Diagnostics of electric arc plasma was carried out. Optical emission and ... in plasma tends to be located at the arc ax...

A.N. Veklich; I.L. Babich

2001-01-01T23:59:59.000Z

76

The Temperature of the Copper Arc  

Science Journals Connector (OSTI)

...Laboratory, General Electric Company. | Journal Article...TEMPERATURE OF THE COPPER ARC By C. G. SUITS RESEARCH LABORATORY, GENERAL ELECTRIC COMPANY Read before the...figure 1, where Fis an arc burning between the electrodes...experiment is a condensed discharge between the electrode...

C. G. Suits

1935-01-01T23:59:59.000Z

77

Local arc discharge mechanism and requirements of power supply in micro-arc oxidation of magnesium alloy  

Science Journals Connector (OSTI)

To study the requirements of the power supply in micro-arc oxidation (MAO) of magnesium alloy, many experiments ... . Based on the experimental results and electric arc theory, the separate local arc discharge me...

Ming Chen; Yuezhou Ma; Yuan Hao

2010-03-01T23:59:59.000Z

78

Low voltage arc formation in railguns  

DOE Patents [OSTI]

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Hawke, R.S.

1985-08-05T23:59:59.000Z

79

Low voltage arc formation in railguns  

DOE Patents [OSTI]

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

Hawke, R.S.

1987-11-17T23:59:59.000Z

80

Low voltage arc formation in railguns  

DOE Patents [OSTI]

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Hawke, Ronald S. (Livermore, CA)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines...

82

Tribological performance of hybrid filtered arc-magnetron coatings...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tribological performance of hybrid filtered arc-magnetron coatings - Part I: Coating deposition process and basic coating Tribological performance of hybrid filtered arc-magnetron...

83

Theoretical analysis of ARC constriction  

SciTech Connect (OSTI)

The physics of the thermionic converter is governed by strong electrode-plasma interactions (emissions surface scattering, charge exchange) and weak interactions (diffusion, radiation) at the maximum interelectrode plasma radius. The physical processes are thus mostly convective in thin sheaths in front of the electrodes and mostly diffusive and radiative in the plasma bulk. The physical boundaries are open boundaries to particle transfer (electrons emitted or absorbed by the electrodes, all particles diffusing through some maximum plasma radius) and to convective, conductive and radiative heat transfer. In a first approximation the thermionic converter may be described by a one-dimensional classical transport theory. The two-dimensional effects may be significant as a result of the sheath sensitivity to radial plasma variations and of the strong sheath-plasma coupling. The current-voltage characteristic of the converter is thus the result of an integrated current density over the collector area for which the boundary conditions at each r determine the regime (ignited/unignited) of the local current density. A current redistribution strongly weighted at small radii (arc constriction) limits the converter performance and opens questions on constriction reduction possibilities. The questions addressed are the followng: (1) what are the main contributors to the loss of current at high voltage in the thermionic converter; and (2) is arc constriction observable theoretically and what are the conditions of its occurrence. The resulting theoretical problem is formulated and results are given. The converter electrical current is estimated directly from the electron and ion particle fluxes based on the spatial distribution of the electron/ion density n, temperatures T/sub e/, T/sub i/, electrical voltage V and on the knowledge of the transport coefficients. (WHK)

Stoenescu, M.L.; Brooks, A.W.; Smith, T.M.

1980-12-01T23:59:59.000Z

84

Magnetic-cusp, cathodic-arc source  

DOE Patents [OSTI]

A magnetic-cusp for a cathodic-arc source wherein the arc is confined to the desired cathode surface, provides a current path for electrons from the cathode to the anode, and utilizes electric and magnetic fields to guide ions from the cathode to a point of use, such as substrates to be coated. The magnetic-cusp insures arc stability by an easy magnetic path from anode to cathode, while the straight-through arrangement leads to high ion transmission. 3 figs.

Falabella, S.

1995-11-21T23:59:59.000Z

85

Achievement Rewards for College Scientists ARCS Foundation, Inc.  

E-Print Network [OSTI]

Achievement Rewards for College Scientists ARCS Foundation, Inc. For more information on how of the ARCS Foundation, Inc. funds seven scholarships for exceptional University of Georgia doctoral students. Available to attend the ARCS Foundation Awards Luncheon in Atlanta on November 21, 2013. ARCS Foundation

Arnold, Jonathan

86

Continuous nanoparticle generation and assembly by atmospheric pressure arc discharge  

E-Print Network [OSTI]

Continuous nanoparticle generation and assembly by atmospheric pressure arc discharge Jesse J. Cole a dc arc discharge plasma. The particles are positively charged by the arc and form a room temperature precursor materials.5,6 High temperature plasmas in the form of dc arc discharges led to the discovery

Jacobs, Heiko O.

87

AdaptiveARC | Open Energy Information  

Open Energy Info (EERE)

AdaptiveARC AdaptiveARC Jump to: navigation, search Name AdaptiveARC Address 7683 Sitio Manana Place Carlsbad, California Zip 92009 Sector Biomass Product Waste-to-clean-energy startup is developing an arc-plasma reactor Website http://www.adaptivearc.com/ Coordinates 33.07959°, -117.22539° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.07959,"lon":-117.22539,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

88

Arc Statistics in Clusters: Galaxy Contribution  

E-Print Network [OSTI]

The frequency with which background galaxies appear as long arcs as a result of gravitational lensing by foreground clusters of galaxies has recently been found to be a very sensitive probe of cosmological models by Bartelmann et al. (1998). They have found that such arcs would be expected far less frequently than observed (by an order of magnitude) in the currently favored model for the universe, with a large cosmological constant $\\Omega_\\Lambda \\sim 0.7$. Here we analyze whether including the effect of cluster galaxies on the likelihood of clusters to generate long-arc images of background galaxies can change the statistics. Taking into account a variety of constraints on the properties of cluster galaxies, we find that there are not enough sufficiently massive galaxies in a cluster for them to significantly enhance the cross section of clusters to generate long arcs. We find that cluster galaxies typically enhance the cross section by only $\\lesssim 15%$.

R. A. Flores; A. H. Maller; J. R. Primack

1999-09-23T23:59:59.000Z

89

Detection of arcs in automotive electrical systems  

E-Print Network [OSTI]

At the present time, there is no established method for the detection of DC electric arcing. This is a concern for forthcoming advanced automotive electrical systems which consist of higher DC electric power bus voltages, ...

Mishrikey, Matthew David

2005-01-01T23:59:59.000Z

90

Heat flux characteristics in an atmospheric double arc argon plasma jet  

SciTech Connect (OSTI)

In this study, the axial evolution of heat flux excited by a double arc argon plasma jet impinging on a flat plate is determined, while the nonstationary behavior of the heat flux is investigated by combined means of the fast Fourier transform, Wigner distribution, and short-time Fourier transform. Two frequency groups (<1 and 2-10 kHz) are identified in both the Fourier spectrum and the time-frequency distributions, which suggest that the nature of fluctuations in the heat flux is strongly associated with the dynamic behavior of the plasma arc and the engulfment of ambient air into different plasma jet regions.

Tu Xin; Yu Liang; Yan Jianhua; Cen Kefa [Zhejiang University, Hangzhou 310027 (China); Cheron, Bruno [UMR 6614 CNRS CORIA, Saint Etienne du Rouvray 76801 (France)

2008-10-13T23:59:59.000Z

91

Dynamic Transmission Electron Microscopy  

SciTech Connect (OSTI)

Dynamic transmission electron microscopy (DTEM) combines the benefits of high spatial resolution electron microscopy with the high temporal resolution of ultrafast lasers. The incorporation of these two components into a single instrument provides a perfect platform for in situ observations of material processes. However, previous DTEM applications have focused on observing structural changes occurring in samples exposed to high vacuum. Therefore, in order to expand the pump-probe experimental regime to more natural environmental conditions, in situ gas and liquid chambers must be coupled with Dynamic TEM. This chapter describes the current and future applications of in situ liquid DTEM to permit time-resolved atomic scale observations in an aqueous environment, Although this chapter focuses mostly on in situ liquid imaging, the same research potential exists for in situ gas experiments and the successful integration of these techniques promises new insights for understanding nanoparticle, catalyst and biological protein dynamics with unprecedented spatiotemporal resolution.

Evans, James E.; Jungjohann, K. L.; Browning, Nigel D.

2012-10-12T23:59:59.000Z

92

Method for gas-metal arc deposition  

DOE Patents [OSTI]

Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment wiht the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite.

Buhrmaster, Carol L. (Corning, NY); Clark, Denis E. (Idaho Falls, ID); Smartt, Herschel B. (Idaho Falls, ID)

1990-01-01T23:59:59.000Z

93

Method for gas-metal arc deposition  

DOE Patents [OSTI]

Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites are disclosed. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment with the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite. 1 fig.

Buhrmaster, C.L.; Clark, D.E.; Smartt, H.B.

1990-11-13T23:59:59.000Z

94

Apparatus for gas-metal arc deposition  

DOE Patents [OSTI]

Apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment with the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspenion of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite.

Buhrmaster, Carol L. (Corning, NY); Clark, Denis E. (Idaho Falls, ID); Smartt, Herschel B. (Idaho Falls, ID)

1991-01-01T23:59:59.000Z

95

Ion source with improved primary arc collimation  

DOE Patents [OSTI]

An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power, thereby preventing the exposure of the anode to the full arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

Dagenhart, William K. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

96

The Consumption of Carbon in the Electric Arc. I. Variation with Current and Arc-Length. II. Influence upon the Luminous Radiation from the Arc  

Science Journals Connector (OSTI)

1 December 1915 research-article The Consumption of Carbon in the Electric Arc. I. Variation with Current and Arc-Length. II. Influence upon the Luminous Radiation from the...

1915-01-01T23:59:59.000Z

97

Vertical Arc for ILC Low Emittance Transport  

SciTech Connect (OSTI)

The design and parameters of a vertical arc for the ILC Low Emittance Transport (LET) are reviewed. A 1 TeV CM ILC which relies upon 30 MV/m accelerating cavities with a packing fraction of 65% will require almost 48 km of main linac, which suggests that the total site length including BDS and bunch compressors will be on the order of 53 km. If built in a laser-straight tunnel with the low-energy ends near the surface, and assuming a perfectly spherical ''cue ball'' planetary surface with radius 6370 km, the collider halls will necessarily be 55 meters below grade, as shown in the top plot of Figure 1. Such depths would demand extensive use of deep tunneling, which would potentially drive up the cost and difficulty of ILC construction. An alternate solution is to use discrete vertical arcs at a few locations to allow a ''piecewise straight'' construction in which the depth of the tunnel below grade does not vary by more than a few meters. This approach is shown schematically in the bottom plot of Figure 1. In this Note we consider the issues for a design with one such vertical arc at the 250 GeV/c point (ie, midway down the linac for 1 TeV CM), and a second arc at the entrance to the BDS (ie, the entire BDS lies in one plane, with vertical arcs at each end).

Tenenbaum, P.; Woodley, M.; /SLAC

2005-06-07T23:59:59.000Z

98

Ion source with improved primary arc collimation  

DOE Patents [OSTI]

An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

Dagenhart, W.K.

1983-12-16T23:59:59.000Z

99

Dynamic  

Office of Legacy Management (LM)

Dynamic Dynamic , and Static , Res.ponse of the Government Oil Shale Mine at ' , . , Rifle, Colorado, to the Rulison Event. , . ; . . DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. p ( y c - - a 2-1 0 -4- REPORT AT (29-2) 914 USBM 1 0 0 1 UNITED STATES DEPARTMENT O F THE I NTERIOR BUREAU OF MINES e s.09 P. L. R U S S E L L RESEARCH D l RECTOR Februory 2, lB7O DYNAMIC AND STATIC RESPONSE 'OF THE GOVERNMENT OIL SHALE MINE A T RIFLE, COLORADO, T O THE, RULISON EVENT ORDER FROM CFSTl A S ~ B ~ &J C / This page intentionally left blank CONTENTS Page . . . . . . . . . . . . . . . . . . . . . . . . . H i s t o r i c . a l Des c r i p t i o n 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3

100

Ion source based on the cathodic arc  

DOE Patents [OSTI]

A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

Sanders, D.M.; Falabella, S.

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Ion source based on the cathodic arc  

DOE Patents [OSTI]

A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles.

Sanders, David M. (Livermore, CA); Falabella, Steven (Livermore, CA)

1994-01-01T23:59:59.000Z

102

CONTROL OF AN ARC DISCHARGE BY MEANS OF A GRID  

Science Journals Connector (OSTI)

CONTROL OF AN ARC DISCHARGE BY MEANS OF A GRID Albert...Research Laboratory, General Electric Co., Schenectady , N. Y. CONTROL OF AN ARC DISCHARGE BY MEANS OF A GRID. | Research Laboratory, General Electric Co., Schenectady , N...

Albert W. Hull; Irving Langmuir

1929-01-01T23:59:59.000Z

103

Fluorination of Arc-Produced Carbon Material Containing Multiwall Nanotubes  

Science Journals Connector (OSTI)

In this work we studied the fluorination process of MWNTs produced in an electric arc. ... Carbon material was synthesized by using a setup for arc-discharge graphite evaporation described elsewhere. ...

Nicolai F. Yudanov; Alexander V. Okotrub; Yuri V. Shubin; Lyudmila I. Yudanova; Lyubov G. Bulusheva; Andrew L. Chuvilin; Jean-Marc Bonard

2002-03-21T23:59:59.000Z

104

Type B Accident Investigation of the Savannah River Site Arc...  

Broader source: Energy.gov (indexed) [DOE]

the Savannah River Site Arc Flash Burn Injury on September 23, 2009, in the D Area Powerhouse Type B Accident Investigation of the Savannah River Site Arc Flash Burn Injury on...

105

Measurement of the temperature of a pulsating electric arc discharge  

Science Journals Connector (OSTI)

A simple method for determining the temperature on the axis of an oscillating arc column is proposed.

A. Marotta

1994-06-01T23:59:59.000Z

106

Achievement Rewards for College Scientists ARCS Foundation, Inc.  

E-Print Network [OSTI]

Achievement Rewards for College Scientists ARCS Foundation, Inc. Biomedical and Health Sciences the Atlanta chapter of the ARCS Foundation, Inc. funds eight scholarships for exceptional University.S. citizenship. · GPA of 3.5 or above. · Available to attend the ARCS Foundation Awards Luncheon in Atlanta

Arnold, Jonathan

107

Decomposition of Naphthalene by dc Gliding Arc Gas Discharge  

Science Journals Connector (OSTI)

Decomposition of Naphthalene by dc Gliding Arc Gas Discharge ... In the air and oxygen gliding arc discharges, the naphthalene degradation is mainly governed by reactions with oxygen-derived radicals. ... Therefore, the local electric field strength is relatively low in argon gliding arc plasma. ...

Liang Yu; Xiaodong Li; Xin Tu; Yu Wang; Shengyong Lu; Jianhua Yan

2009-12-11T23:59:59.000Z

108

Way to reduce arc voltage losses in hybrid thermionic converters  

SciTech Connect (OSTI)

Experimental results are reported concerning the output and emission characteristics of the arc and hybrid regimes in a plane-parallel thermionic converter with Pt--Zr--O electrode pair. It is shown that arc voltage losses can be reduced to values below those obtainable in ordinary arc thermionic converters.

Tskhakaya, V.K.; Yarygin, V.I.

1982-03-01T23:59:59.000Z

109

Calculating the parameters of electric-arc heaters with gas-stabilized arcs  

Science Journals Connector (OSTI)

We used a turbulent model of a longitudinally streamlined electric arc to derive an analytical solution for the ... of the distribution of the primary flow and discharge parameters in a cylindrical discharge chan...

N. A. Zyrichev

1969-07-01T23:59:59.000Z

110

Gas tungsten arc welder with electrode grinder  

DOE Patents [OSTI]

A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

Christiansen, David W. (Kennewick, WA); Brown, William F. (West Richland, WA)

1984-01-01T23:59:59.000Z

111

Dynamics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hydration Hydration Water on Rutile Studied by Backscattering Neutron Spectroscopy and Molecular Dynamics Simulation E. Mamontov,* ,† D. J. Wesolowski, ‡ L. Vlcek, § P. T. Cummings, §,| J. Rosenqvist, ‡ W. Wang, ⊥ and D. R. Cole ‡ Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6473, Chemical Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, Department of Chemical Engineering, Vanderbilt UniVersity, NashVille, Tennessee 37235-1604, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6496, and EnVironmental Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6036 ReceiVed: December 20, 2007; ReVised Manuscript ReceiVed: June 4, 2008 The high energy resolution, coupled with the wide dynamic range, of the new backscattering

112

Page 1 of 2 -ARC Cost Transfer Guide v. 06/14/13 ARC SPONSORED PROJECT COST TRANSFER GUIDE  

E-Print Network [OSTI]

Page 1 of 2 - ARC Cost Transfer Guide v. 06/14/13 ARC SPONSORED PROJECT COST TRANSFER GUIDE There are three ways to move expenditures onto, off of, or between Sponsored Projects in ARC: AP Journal Voucher in which the voucher accounting date falls, and they are being moved to or between Sponsored Projects GL

Hone, James

113

Hybrid Arc Cell Studies: Status Report  

SciTech Connect (OSTI)

I report on the status, at the end of FY12, of the studies of an arc cell for a hybrid synchrotron accelerating from 375 GeV/c to 750 GeV/c in momentum. Garren produced a complete lattice that gives a good outline of the structure of a hybrid synchrotron lattice. It is, however, lacking in some details: it does not maintain a constant time of flight, it lacks chromaticity correction, its cell structure is not ideal for removing aberrations from chromaticity correction, and it probably needs more space between magnets. I have begun studying cell structures for the arc cells to optimize the lattice performance and cost. I present some preliminary results for two magnets per half cell. I then discuss difficulties encountered, some preliminary attempts at resolving them, and the future plans for this work.

Berg J. S.

2012-09-28T23:59:59.000Z

114

Cathodic Vacuum Arc Plasma of Thallium  

SciTech Connect (OSTI)

Thallium arc plasma was investigated in a vacuum arc ionsource. As expected from previous consideration of cathode materials inthe Periodic Table of the Elements, thallium plasma shows lead-likebehavior. Its mean ion charge state exceeds 2.0 immediately after arctriggering, reaches the predicted 1.60 and 1.45 after about 100 microsecand 150 microsec, respectively. The most likely ion velocity is initially8000 m/s and decays to 6500 m/s and 6200 m/s after 100 microsec and 150microsec, respectively. Both ion charge states and ion velocities decayfurther towards steady state values, which are not reached within the 300microsec pulses used here. It is argued that the exceptionally high vaporpressure and charge exchange reactions are associated with theestablishment of steady state ion values.

Yushkov, Georgy Yu.; Anders, Andre

2006-10-02T23:59:59.000Z

115

Electrical Safety and Arc Flash Protections  

SciTech Connect (OSTI)

Over the past four years, the Electrical Safety Program at PPPL has evolved in addressing changing regulatory requirements and lessons learned from accident events, particularly in regards to arc flash hazards and implementing NFPA 70E requirements. This presentation will discuss PPPL's approaches to the areas of electrical hazards evaluation, both shock and arc flash; engineered solutions for hazards mitigation such as remote racking of medium voltage breakers, operational changes for hazards avoidance, targeted personnel training and hazard appropriate personal protective equipment. Practical solutions for nominal voltage identification and zero voltage checks for lockout/tagout will also be covered. Finally, we will review the value of a comprehensive electrical drawing program, employee attitudes expressed as a personal safety work ethic, integrated safety management, and sustained management support for continuous safety improvement.

R. Camp

2008-03-04T23:59:59.000Z

116

Delivery quality assurance with ArcCHECK  

SciTech Connect (OSTI)

Radiation therapy requires delivery quality assurance (DQA) to ensure that treatment is accurate and closely follows the plan. We report our experience with the ArcCHECK phantom and investigate its potential optimization for the DQA process. One-hundred seventy DQA plans from 84 patients were studied. Plans were classified into 2 groups: those with the target situated on the diodes of the ArcCHECK (D plans) and those with the target situated at the center (C plans). Gamma pass rates for 8 target sites were examined. The parameters used to analyze the data included 3%/3 mm with the Van Dyk percent difference criteria (VD) on, 3%/3 mm with the VD off, 2%/2 mm with the VD on, and x/3 mm with the VD on and the percentage dosimetric agreement “x” for diode plans adjusted. D plans typically displayed maximum planned dose (MPD) on the cylindrical surface containing ArcCHECK diodes than center plans, resulting in inflated gamma pass rates. When this was taken into account by adjusting the percentage dosimetric agreement, C plans outperformed D plans by an average of 3.5%. ArcCHECK can streamline the DQA process, consuming less time and resources than radiographic films. It is unnecessary to generate 2 DQA plans for each patient; a single center plan will suffice. Six of 8 target sites consistently displayed pass rates well within our acceptance criteria; the lesser performance of head and neck and spinal sites can be attributed to marginally lower doses and increased high gradient of plans.

Neilson, Christopher; Klein, Michael; Barnett, Rob [London Regional Cancer Program, London Health Sciences Centre, London, Ontario (Canada); Yartsev, Slav, E-mail: slav.yartsev@lhsc.on.ca [London Regional Cancer Program, London Health Sciences Centre, London, Ontario (Canada)

2013-04-01T23:59:59.000Z

117

Volumetric modulated arc radiotherapy for esophageal cancer  

SciTech Connect (OSTI)

A treatment planning study was performed to evaluate the performance of volumetric arc modulation with RapidArc (RA) against 3D conformal radiation therapy (3D-CRT) and conventional intensity-modulated radiation therapy (IMRT) techniques for esophageal cancer. Computed tomgraphy scans of 10 patients were included in the study. 3D-CRT, 4-field IMRT, and single-arc and double-arc RA plans were generated with the aim to spare organs at risk (OAR) and healthy tissue while enforcing highly conformal target coverage. The planning objective was to deliver 54 Gy to the planning target volume (PTV) in 30 fractions. Plans were evaluated based on target conformity and dose-volume histograms of organs at risk (lung, spinal cord, and heart). The monitor unit (MU) and treatment delivery time were also evaluated to measure the treatment efficiency. The IMRT plan improves target conformity and spares OAR when compared with 3D-CRT. Target conformity improved with RA plans compared with IMRT. The mean lung dose was similar in all techniques. However, RA plans showed a reduction in the volume of the lung irradiated at V{sub 20Gy} and V{sub 30Gy} dose levels (range, 4.62-17.98%) compared with IMRT plans. The mean dose and D{sub 35%} of heart for the RA plans were better than the IMRT by 0.5-5.8%. Mean V{sub 10Gy} and integral dose to healthy tissue were almost similar in all techniques. But RA plans resulted in a reduced low-level dose bath (15-20 Gy) in the range of 14-16% compared with IMRT plans. The average MU needed to deliver the prescribed dose by RA technique was reduced by 20-25% compared with IMRT technique. The preliminary study on RA for esophageal cancers showed improvements in sparing OAR and healthy tissue with reduced beam-on time, whereas only double-arc RA offered improved target coverage compared with IMRT and 3D-CRT plans.

Vivekanandan, Nagarajan, E-mail: viveknaren@hotmail.com [Department of Medical Physics, Cancer Institute, Chennai (India); Sriram, Padmanaban; Syam Kumar, S.A.; Bhuvaneswari, Narayanan; Saranya, Kamalakannan [Department of Medical Physics, Cancer Institute, Chennai (India)

2012-04-01T23:59:59.000Z

118

Arc Flash Boundary Calculations Using Computer Software Tools  

SciTech Connect (OSTI)

Arc Flash Protection boundary calculations have become easier to perform with the availability of personal computer software. These programs incorporate arc flash protection boundary formulas for different voltage and current levels, calculate the bolted fault current at each bus, and use built in time-current coordination curves to determine the clearing time of protective devices in the system. Results of the arc flash protection boundary calculations can be presented in several different forms--as an annotation to the one-line diagram, as a table of arc flash protection boundary distances, and as printed placards to be attached to the appropriate equipment. Basic arc flash protection boundary principles are presented in this paper along with several helpful suggestions for performing arc flash protection boundary calculations.

Gibbs, M.D.

2005-01-07T23:59:59.000Z

119

Physics of arcing, and implications to sputter deposition  

SciTech Connect (OSTI)

Arcing is a well-known, unwanted discharge regime observed on the surface of sputtering targets. The discharge voltage breaks down to less than 50 V while the current jumps to elevated levels. Arcing is unwanted because it prevents uniform deposition and creates particulates. The issue of arcing has been dealt with by target surface conditioning and by using modern power supplies that have arc suppression incorporated. With increasing quality requirements in terms of uniformity of coatings, and absence of particulates, especially for electrochromic and other advanced coatings applications, the issue of arcing warrants a closer examination with the goal to find other, physics-based, and hopefully better approaches of arcing prevention. From a physics point of view, the onset of arcing is nothing else than the transition of the discharge to a cathodic arc mode, which is characterized by the ignition of non-stationary arc spots. Arc spots operate by a sequence of microexplosions, enabling explosive electron emission, as opposed to secondary electron emission. Arc spots and their fragments have a size distribution in the micrometer and sub-micrometer range, and a characteristic time distribution that has components shorter than microseconds. Understanding the ignition conditions of arc spots are of central physical interest. Spot ignition is associated with electric field enhancement, which can be of geometric nature (roughness,particles), or chemical nature (e.g. oxide formation) and related local accumulation of surface charge. Therefore, it is clear that these issues are of particular concern when operating with high-density plasmas, such as in high-power pulsed sputtering, and when using reactive sputter gases.

Anders, Andre

2003-12-15T23:59:59.000Z

120

Influence of argon and oxygen on charge-state-resolved ion energy distributions of filtered aluminum arcs  

E-Print Network [OSTI]

energy distributions of filtered aluminum arcs Johanna Roséndistributions (IEDs) in filtered aluminum vacuum arc plasmasfor vacuum arc plasmas. Aluminum plasma, for example,

Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

A Miocene Island-Arc Volcanic Seamount- The Takashibiyama Formation...  

Open Energy Info (EERE)

Island-Arc Volcanic Seamount- The Takashibiyama Formation, Shimane Peninsula, Sw Japan Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A...

122

A New Survey for Giant Arcs  

SciTech Connect (OSTI)

We report on the first results of an imaging survey to detect strong gravitational lensing targeting the richest clusters selected from the photometric data of the Sloan Digital Sky Survey (SDSS) with follow-up deep imaging observations from the Wisconsin Indiana Yale NOAO (WIYN) 3.5m telescope and the University of Hawaii 88-inch telescope (UH88). The clusters are selected from an area of 8000 deg{sup 2} using the Red Cluster Sequence technique and span the redshift range 0.1 {approx}< z {approx}< 0.6, corresponding to a comoving cosmological volume of {approx} 2Gpc{sup 3}. Our imaging survey thus targets a volume more than an order of magnitude larger than any previous search. A total of 240 clusters were imaged of which 141 had sub-arcsecond image quality. Our survey has uncovered 16 new lensing clusters with definite giant arcs, an additional 12 systems for which the lensing interpretation is very likely, and 9 possible lenses which contain shorter arclets or candidate arcs which are less certain and will require further observations to confirm their lensing origin. The number of new cluster lenses detected in this survey is likely > 30. Among these new systems are several of the most dramatic examples of strong gravitational lensing ever discovered with multiple bright arcs at large angular separation. These will likely become 'poster-child' gravitational lenses similar to Abell 1689 and CL0024+1654. The new lenses discovered in this survey will enable future systematic studies of the statistics of strong lensing and its implications for cosmology and our structure formation paradigm.

Hennawi, Joseph F.; Gladders, Michael D.; Oguri, Masamune; Dalal, Neal; Koester, Benjamin; Natarajan, Priyamvada; Strauss, Michael A.; Inada, Naohisa; Kayo, Issha; Lin,; Lampeitl, Hubert; Annis, James; Bahcall, Neta A.; Schneider, Donald P.

2006-11-15T23:59:59.000Z

123

Sensing the gas metal arc welding process  

SciTech Connect (OSTI)

Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-bypass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

Carlson, N.M.; Johnson, J.A.; Smartt, H.B.; Watkins, A.D.; Larsen, E.D.; Taylor, P.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Waddoups, M.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1992-10-01T23:59:59.000Z

124

Sensing the gas metal arc welding process  

SciTech Connect (OSTI)

Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-bypass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

Carlson, N.M.; Johnson, J.A.; Smartt, H.B.; Watkins, A.D.; Larsen, E.D.; Taylor, P.L. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Waddoups, M.A. (Idaho National Engineering Lab., Idaho Falls, ID (United States))

1992-01-01T23:59:59.000Z

125

Modeling of thermal plasma arc technology FY 1994 report  

SciTech Connect (OSTI)

The thermal plasma arc process is under consideration to thermally treat hazardous and radioactive waste. A computer model for the thermal plasma arc technology was designed as a tool to aid in the development and use of the plasma arc-Joule beating process. The value of this computer model is to: (a) aid in understanding the plasma arc-Joule beating process as applied to buried waste or exhumed buried waste, (b) help design melter geometry and electrode configuration, (c) calculate the process capability of vitrifying waste (i.e., tons/hour), (d) develop efficient plasma and melter operating conditions to optimize the process and/or reduce safety hazards, (e) calculate chemical reactions during treatment of waste to track chemical composition of off-gas products, and composition of final vitrified waste form and (f) help compare the designs of different plasma-arc facilities. A steady-state model of a two-dimensional axisymmetric transferred plasma arc has been developed and validated. A parametric analysis was performed that studied the effects of arc length, plasma gas composition, and input power on the temperatures and velocity profiles of the slag and plasma gas. A two-dimensional transient thermo-fluid model of the US Bureau of Mines plasma arc melter has been developed. This model includes the growth of a slag pool. The thermo-fluid model is used to predict the temperature and pressure fields within a plasma arc furnace. An analysis was performed to determine the effects of a molten metal pool on the temperature, velocity, and voltage fields within the slag. A robust and accurate model for the chemical equilibrium calculations has been selected to determine chemical composition of final waste form and off-gas based on the temperatures and pressures within the plasma-arc furnace. A chemical database has been selected. The database is based on the materials to be processed in the plasma arc furnaces.

Hawkes, G.L.; Nguyen, H.D.; Paik, S.; McKellar, M.G.

1995-03-01T23:59:59.000Z

126

E-Print Network 3.0 - arc magmatism isotopic Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

& Nakamura (1993) Nature 370 e.g. Izu arc: Ishikawa & Nakamura (1993) Nature 370 Boron isotopes help... --Th isotopes in arc magmasTh isotopes in arc magmas For equilibrium:...

127

E-Print Network 3.0 - arc northwesternmost california Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

365 ARC JIW Engineering Design Requirements (4... 201 2. ARC 203 2. ARC 204 (studio) 3. PHY 103 3. PHY ... Source: Bou-Zeid, Elie - Department of Civil and Environmental...

128

E-Print Network 3.0 - arc detector system Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by hand later) Summary: . The spatial resolution is approximately 1 arc sec in the E-W direction and 2 arc sec along the slit (N... ,0) (3,0) (0,910) Slit n ? (arc sec 2 ) ...

129

E-Print Network 3.0 - assisted non-consumable arc Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sample search results for: assisted non-consumable arc Page: << < 1 2 3 4 5 > >> 1 GIS by ESRITM What is ArcGIS Summary: GIS by ESRITM What is ArcGIS TM ? 12;Copyright ...

130

Development of a ReaxFF Reactive Force Field for Ettringite and Study of its Mechanical Failure Modes from Reactive Dynamics Simulations  

Science Journals Connector (OSTI)

Development of a ReaxFF Reactive Force Field for Ettringite and Study of its Mechanical Failure Modes from Reactive Dynamics Simulations ... Ettringite is a hexacalcium aluminate trisulfate hydrate mineral that forms during Portland cement hydration. ... Here, we report on the development of this ReaxFF force field and on its validation and application using reactive molecular dynamics (RMD) simulations to characterize and understand the elastic, plastic, and failure response of ettringite at the atomic scale. ...

Lianchi Liu; Andres Jaramillo-Botero; William A. Goddard; III; Huai Sun

2012-03-13T23:59:59.000Z

131

Arc Geometry and Algebra: Foliations, Moduli Spaces, String ...  

E-Print Network [OSTI]

exhaustive if wti(?) = 0 for all i. We set Arcs g(r ?1) ? As g,r and DArcs g(r ?1) ? Ds g,r to be the subsets of exhaustive elements. We furthermore set Arc(n) = ?g,

2012-05-02T23:59:59.000Z

132

Connecting ARC/INFO and SNACTor Project Report  

E-Print Network [OSTI]

Connecting ARC/INFO and SNACTor Project Report June 1991 Stuart C. Shapiro, Hans Chalupsky;Connecting ARC/INFO* and SNACTor --- Project Report1 Stuart C. Shapiro2 , Hans Chalupsky2 and Hsueh and reasoning system developed by Stuart C. Shapiro et al. at the State University of New York at Buffalo

California at Santa Barbara, University of

133

Mechanism of carbon nanostructure synthesis in arc plasma  

SciTech Connect (OSTI)

Plasma enhanced techniques are widely used for synthesis of carbon nanostructures. The primary focus of this paper is to summarize recent experimental and theoretical advances in understanding of single-wall carbon nanotube (SWNT) synthesis mechanism in arcs, and to describe methods of controlling arc plasma parameters. Fundamental issues related to synthesis of SWNTs, which is a relationship between plasma parameters and SWNT characteristics are considered. It is shown that characteristics of synthesized SWNTs can be altered by varying plasma parameters. Effects of electrical and magnetic fields applied during SWNT synthesis in arc plasma are explored. Magnetic field has a profound effect on the diameter, chirality, and length of a SWNT synthesized in the arc plasma. An average length of SWNT increases by a factor of 2 in discharge with magnetic field and an amount of long nanotubes with the length above 5 {mu}m also increases in comparison with that observed in the discharge without a magnetic field. In addition, synthesis of a few-layer graphene in a magnetic field presence is discovered. A coupled model of plasma-electrode phenomena in atmospheric-pressure anodic arc in helium is described. Calculations indicate that substantial fraction of the current at the cathode is conducted by ions (0.7-0.9 of the total current). It is shown that nonmonotonic behavior of the arc current-voltage characteristic can be reproduced taking into account the experimentally observed dependence of the arc radius on arc current.

Keidar, M.; Shashurin, A.; Volotskova, O. [George Washington University, Washington, DC 20052 (United States); Raitses, Y. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Beilis, I. I. [Tel Aviv University, Tel Aviv 69978 (Israel)

2010-05-15T23:59:59.000Z

134

Darwin: The Third DOE ARM TWP ARCS Site  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Darwin: The Third DOE ARM TWP ARCS Site Darwin: The Third DOE ARM TWP ARCS Site W. E. Clements and L. Jones Los Alamos National Laboratory, Los Alamos, New Mexico T. Baldwin Special Services Unit Australian Bureau of Meteorology Melbourne, Australia K. Nitschke South Pacific Regional Environment Programme Apia, Samoa Introduction The U.S. Department of Energy's (DOE's) Atmospheric Radiation Measurement (ARM) Program began operations in its Tropical Western Pacific (TWP) locale in October 1996 when the first Atmospheric Radiation and Cloud Station (ARCS) began collecting data on Manus Island in Papua New Guinea (PNG). Two years later, in November 1998 a second ARCS began operations on the island of Nauru in the Central Pacific. Now a third ARCS has begun collecting data in Darwin, Australia. See Figure 1 for

135

Type A Investigation of the Electrical Arc Injury at the Stanford...  

Office of Environmental Management (EM)

of the Electrical Arc Injury at the Stanford Linear Accelerator Complex on October 11, 2004 Type A Investigation of the Electrical Arc Injury at the Stanford Linear Accelerator...

136

E-Print Network 3.0 - area filtered arc Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Electrical and Computer Engineering, University of Kentucky Collection: Engineering 3 GIS by ESRITM What is ArcGIS Summary: and terrainmodelingcapabilities. ArcGIS 3D Analyst...

137

E-Print Network 3.0 - andean arc magmatism Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

arc in central Novaya Zemlya, Arctic Russia... - genian magmatic arc. Zircon and titanite in four samples from Mashigin Fjord and Matochkin Strait yield U... ). The events at...

138

Physical characteristics of gliding arc discharge plasma generated in a laval nozzle  

SciTech Connect (OSTI)

The dynamic behavior of gliding arc discharge generated in a Laval nozzle has been investigated by electrical diagnostics and a high-speed camera. The results show that the voltage waveform keeps the initial shape as the gas flow rate is small, while it becomes less stable with increasing flow rate. During the first half of a cycle, the voltage rises and after that it decreases. In nitrogen and oxygen, the break down voltage for the arc is between 3.3 and 5.5 kV, while it is between 3.3-7.5 kV in air. The waveform of current I remains almost stable; and for nitrogen and oxygen, the maximum value of current I is between 0.28 and 0.46 A. With increasing flow rate, the power consumption in air first increases and then decreases; it remains in the range of 110-217 W, and gradually increases in nitrogen and oxygen. The power consumption in oxygen is lower than that in nitrogen; the input of the energy density decreases with increasing flow rate for all the three gases. The development of the arc is tracked and recorded by a high-speed camera. The cycle is stable at 10 ms for flow rates up to 1 m{sup 3} h{sup -1}. At a higher flow rate, the cycle becomes unstable.

Lu, S. Y.; Sun, X. M.; Li, X. D.; Yan, J. H. [State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027 (China); Du, C. M. [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

2012-07-15T23:59:59.000Z

139

An algorithm to calculate a collapsed arc dose matrix in volumetric modulated arc therapy  

SciTech Connect (OSTI)

Purpose: The delivery of volumetric modulated arc therapy (VMAT) is more complex than other conformal radiotherapy techniques. In this work, the authors present the feasibility of performing routine verification of VMAT delivery using a dose matrix measured by a gantry mounted 2D ion chamber array and corresponding dose matrix calculated by an inhouse developed algorithm.Methods: Pinnacle, v9.0, treatment planning system (TPS) was used in this study to generate VMAT plans for a 6 MV photon beam from an Elekta-Synergy linear accelerator. An algorithm was developed and implemented with inhouse computer code to calculate the dose matrix resulting from a VMAT arc in a plane perpendicular to the beam at isocenter. The algorithm was validated using measurement of standard patterns and clinical VMAT plans with a 2D ion chamber array. The clinical VMAT plans were also validated using ArcCHECK measurements. The measured and calculated dose matrices were compared using gamma ({gamma}) analysis with 3%/3 mm criteria and {gamma} tolerance of 1.Results: The dose matrix comparison of standard patterns has shown excellent agreement with the mean {gamma} pass rate 97.7 ({sigma}= 0.4)%. The validation of clinical VMAT plans using the dose matrix predicted by the algorithm and the corresponding measured dose matrices also showed good agreement with the mean {gamma} pass rate of 97.6 ({sigma}= 1.6)%. The validation of clinical VMAT plans using ArcCHECK measurements showed a mean pass rate of 95.6 ({sigma}= 1.8)%.Conclusions: The developed algorithm was shown to accurately predict the dose matrix, in a plane perpendicular to the beam, by considering all possible leaf trajectories in a VMAT delivery. This enables the verification of VMAT delivery using a 2D array detector mounted on a treatment head.

Arumugam, Sankar; Xing Aitang [Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, New South Wales 2170 (Australia); Jameson, Michael [Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, New South Wales 2170 (Australia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 (Australia); Holloway, Lois [Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, New South Wales 2170 (Australia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 (Australia); South West Clinical School, University of New South Wales, Sydney, New South Wales 2052 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

2013-07-15T23:59:59.000Z

140

Gamma-Normal Probability Distribution Arc Length  

E-Print Network [OSTI]

2Faculty of Industrial Engineering, Iran University of Science and Technology, Tehran, Iran. Abstract. We propose a dynamic program to find the shortest path in

Hesam

2014-11-04T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Arc Energy Estimations: Applications in Lightning-Induced Concrete Spall  

SciTech Connect (OSTI)

After lightning contacts a building, the possibility of a physical break in its conductive path to ground may exist. Given such a break, an electric field may develop across the gap until it exceeds the breakdown strength of the non-conducting, or dielectric, material. Breakdown subsequently occurs and energy is dissipated during the development of an arc channel. If the dielectric is concrete, a concern exists that the energy available for arc formation may be capable of launching pieces of spall into sensitive equipment. This paper discusses the mechanisms of energy dissipation in arc formation and quantifies the energy available for concrete spall.

Tully, L K; Ong, M M

2008-06-03T23:59:59.000Z

142

Numerical simulation of carbon arc discharge for nanoparticle synthesis  

SciTech Connect (OSTI)

Arc discharge with catalyst-filled carbon anode in helium background was used for the synthesis of carbon nanoparticles. In this paper, we present the results of numerical simulation of carbon arc discharges with arc current varying from 10 A to 100 A in a background gas pressure of 68 kPa. Anode sublimation rate and current voltage characteristics are compared with experiments. Distribution of temperature and species density, which is important for the estimation of the growth of nanoparticles, is obtained. The probable location of nanoparticle growth region is identified based on the temperature range for the formation of catalyst clusters.

Kundrapu, M.; Keidar, M. [Department of Mechanical and Aerospace Engineering, George Washington University, Washington, DC 20052 (United States)

2012-07-15T23:59:59.000Z

143

E-Print Network 3.0 - arc plasma gun Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

gun Search Powered by Explorit Topic List Advanced Search Sample search results for: arc plasma gun...

144

FusionArc optimization: A hybrid volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) planning strategy  

SciTech Connect (OSTI)

Purpose: To introduce a hybrid volumetric modulated arc therapy/intensity modulated radiation therapy (VMAT/IMRT) optimization strategy called FusionArc that combines the delivery efficiency of single-arc VMAT with the potentially desirable intensity modulation possible with IMRT.Methods: A beamlet-based inverse planning system was enhanced to combine the advantages of VMAT and IMRT into one comprehensive technique. In the hybrid strategy, baseline single-arc VMAT plans are optimized and then the current cost function gradients with respect to the beamlets are used to define a metric for predicting which beam angles would benefit from further intensity modulation. Beams with the highest metric values (called the gradient factor) are converted from VMAT apertures to IMRT fluence, and the optimization proceeds with the mixed variable set until convergence or until additional beams are selected for conversion. One phantom and two clinical cases were used to validate the gradient factor and characterize the FusionArc strategy. Comparisons were made between standard IMRT, single-arc VMAT, and FusionArc plans with one to five IMRT/hybrid beams.Results: The gradient factor was found to be highly predictive of the VMAT angles that would benefit plan quality the most from beam modulation. Over the three cases studied, a FusionArc plan with three converted beams achieved superior dosimetric quality with reductions in final cost ranging from 26.4% to 48.1% compared to single-arc VMAT. Additionally, the three beam FusionArc plans required 22.4%-43.7% fewer MU/Gy than a seven beam IMRT plan. While the FusionArc plans with five converted beams offer larger reductions in final cost-32.9%-55.2% compared to single-arc VMAT-the decrease in MU/Gy compared to IMRT was noticeably smaller at 12.2%-18.5%, when compared to IMRT.Conclusions: A hybrid VMAT/IMRT strategy was implemented to find a high quality compromise between gantry-angle and intensity-based degrees of freedom. This optimization method will allow patients to be simultaneously planned for dosimetric quality and delivery efficiency without switching between delivery techniques. Example phantom and clinical cases suggest that the conversion of only three VMAT segments to modulated beams may result in a good combination of quality and efficiency.

Matuszak, Martha M.; McShan, Daniel L.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Steers, Jennifer M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 and Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Long, Troy; Edwin Romeijn, H. [Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Fraass, Benedick A. [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California 90048 (United States)

2013-07-15T23:59:59.000Z

145

DOE Solar Decathlon: News Blog » SCI-Arc/Caltech  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

SCI-Arc/Caltech SCI-Arc/Caltech Below you will find Solar Decathlon news from the SCI-Arc/Caltech archive, sorted by date. CHIP House Takes Design to Different Heights (Literally) Friday, May 13, 2011 By April Saylor Editor's Note: This entry has been cross-posted from DOE's Energy Blog. In honor of the U.S. Department of Energy Solar Decathlon-which challenges 20 collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive-we are profiling each of the 20 teams participating in the competition. The students from the Southern California Institute of Architecture and California Institute of Technology, otherwise known as the SCI-Arc/Caltech team, have teamed up to take an interesting approach to the design of their

146

Capabilities of the ARCS Instrument - ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Capabilities of the ARCS Instrument Capabilities of the ARCS Instrument ARCS Overview The wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source (SNS) is optimized to provide a high neutron flux at the sample position with a large solid angle of detector coverage. The instrument incorporates modern neutron instrumentation, such as an elliptically focused neutron guide, high speed magnetic bearing choppers, and a massive array of 3He linear position sensitive detectors. Novel features of the spectrometer include the use of a large gate valve between the sample and detector vacuum chambers and the placement of the detectors within the vacuum, both of which provide a window-free final flight path to minimize background scattering while allowing rapid changing of the sample and

147

Arc Vault Significantly Reduces Electrical Hazards | GE Global...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The transfer of arc flash energy is accomplished by triggering an ablative plasma gun to generate a 3-phase fault within a safe containment. The plasma gun operates in few...

148

Measurement of total ion current from vacuum arc plasmasources  

SciTech Connect (OSTI)

The total ion current generated by a vacuum arc plasma source was measured. The discharge system investigated allowed ion collection from the arc plasma streaming through a hemispherical mesh anode with geometric transparency of 72 percent. A range of different cathode materials was investigated, and the arc current was varied over the range 50-500 A. We find that the normalized ion current (Iion/Iarc) depends on the cathode material, with values in the range from 5 percent to 19 percent and generally greater for elements of low cohesive energy. The application of a strong axial magnetic field in the cathode and arc region leads to increased normalized ion current, but only by virtue of enhanced ion charge states formed in a strong magnetic field.

Oks, Efim M.; Savkin, Konstantin P.; Yushkov, Georgiu Yu.; Nikolaev, Alexey G.; Anders, A.; Brown, Ian G.

2005-07-01T23:59:59.000Z

149

Micro-arc oxidation coatings on Mg-Li alloys  

Science Journals Connector (OSTI)

Micro-arc oxidation (MAO) method was used for the...in-situ fabricated on the Mg-Li alloy. The morphology feature, phase composition, and corrosion-resistance of the formed ceramic coatings were studied by SEM, X...

Yongjun Xu; Kang Li; Zhongping Yao; Zhaohua Jiang; Milin Zhang

2009-04-01T23:59:59.000Z

150

Type B Accident Investigation of the Arc Flash at Brookhaven...  

Broader source: Energy.gov (indexed) [DOE]

B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006 More Documents & Publications DOE-HDBK-1092-1998 DOE-HDBK-1092-2004 DOE-HDBK-1092-2013...

151

Problems of physical modeling of electric-arc discharges  

Science Journals Connector (OSTI)

Special features of physical modeling of high-current arc discharges are considered. It is shown that the employment of dimensionless criterial expressions makes it possible to establish only approximate simil...

O. I. Yas'ko

152

Electric Parameters of the D.C. Carbon Arc  

Science Journals Connector (OSTI)

The basic electric parameters of an arc discharge are the current strength (i) and the voltage drop across the gap (V). Both quantities can be measured without difficulty. In general, a relationship between V and...

P. W. J. M. Boumans

1966-01-01T23:59:59.000Z

153

Effect of electric arc discharge on hypersonic blunt body drag  

Science Journals Connector (OSTI)

Experimental results on the effect of energy deposition using an electric arc discharge, upstream of a 60°...half angle blunt cone configuration in a hypersonic flow is reported.Investigations involving drag meas...

K. Satheesh; G. Jagadeesh

2009-01-01T23:59:59.000Z

154

Velocity of the electric arc in a plasmatron discharge chamber  

Science Journals Connector (OSTI)

An experimental investigation of the velocity of a high-current arc with air injection in the discharge chamber of a coaxial sectioned plasmatron is described. The experiments showed that the velocity of the c...

A. S. Shaboltas

1969-09-01T23:59:59.000Z

155

A forevacuum pulse arc-discharge-based plasma electron source  

Science Journals Connector (OSTI)

An arc-discharge-based electron source is described, which is designed for forming a pulsed wideaperture electron beam in the forevacuum pressure range (4...2 in the submillisecond range of pulse durations. The c...

A. V. Kazakov; V. A. Burdovitsin; A. V. Medovnik…

2013-11-01T23:59:59.000Z

156

Synthesis of silicon nanotubes by DC arc plasma method  

SciTech Connect (OSTI)

Plasma synthesis is a novel technique of synthesis of nanomaterials as they provide high rate of production and promote metastable reactions. Very thin walled silicon nanotubes were synthesized in a DC direct arc thermal plasma reactor. The effect of parameters of synthesis i.e. arc current and presence of hydrogen on the morphology of Si nanoparticles is reported. Silicon nanotubes were characterized by Transmission Electron Microscopy (TEM), Local Energy Dispersive X-ray analysis (EDAX), and Scanning Tunneling Microscopy (STM).

Tank, C. M.; Bhoraskar, S. V.; Mathe, V. L. [Department of Physics, University of Pune, Pune-7, Maharashtra (India)

2012-06-05T23:59:59.000Z

157

JOURNAL DE PPHYSIQUE THEORY OF =LOW CATHODEINATMOSPHERIC ARC INNOBLE GAS  

E-Print Network [OSTI]

. S. S. R. 1. The hollow arc discharge i n cylindrical hollow cathode (IiC) with s l i g h t l yJOURNAL DE PPHYSIQUE THEORY OF =LOW CATHODEINATMOSPHERIC ARC INNOBLE GAS F.G. Baksht, A.B. Rybakov. 4-22742~-j,2x$-.@+.j# .Ya4z(5) 4. he pre-electr*e ionization ~ w e r(L df 9 e L 4 - ~ = d ; ) must

Boyer, Edmond

158

Experimental Study on Gasoline Reforming Assisted by Nonthermal Arc Discharge  

Science Journals Connector (OSTI)

The gasoline conversion efficiency decreased when the electric discharge regime was changing from continuous to gliding arc and from gliding to streamer. ... Compared with catalytic reformers, plasma devices have so far lower performances, which is explained by the early stage of research on nonthermal plasma reforming and the need of an external energy input (electricity). ... and design of the plasma reactor, composed of two gliding arc discharges in series, were detailed. ...

Jean-Damien Rollier; José Gonzalez-Aguilar; Guillaume Petitpas; Adeline Darmon; Laurent Fulcheri; Rudolf Metkemeijer

2007-12-06T23:59:59.000Z

159

Lightning Induced Arcing an LDRD Report  

SciTech Connect (OSTI)

The purpose of this research was to develop a science-based understanding of the early-time behavior of electric surface arcing in air at atmospheric pressure. As a first step towards accomplishing this, we used a kinetic approach to model an electron swarm as it evolved in a neutral gas under the influence of an applied electric field. A computer code was written in which pseudo-particles, each representing some number of electrons, were accelerated by an electric field. The electric field due to the charged particles was calculated efficiently using a tree algorithm. Collision of the electrons with the background gas led to the creation of new particles through the processes of ionization and photoionization. These processes were accounted for using measured cross-section data and Monte Carlo methods. A dielectric half-space was modeled by imaging the charges in its surface. Secondary electron emission from the surface, resulting in surface charging, was also calculated. Simulation results show the characteristics of a streamer in three dimensions. A numerical instability was encountered before the streamer matured to form branching.

JORGENSON,ROY E.; WARNE,LARRY K.; KUNHARDT,ERICH E.

2000-12-01T23:59:59.000Z

160

Measurements of the total ion flux from vacuum arc cathodespots  

SciTech Connect (OSTI)

The ion flux from vacuum arc cathode spots was measured in two vacuum arc systems. The first was a vacuum arc ion source which was modified allowing us to collect ions from arc plasma streaming through an anode mesh. The second discharge system essentially consisted of a cathode placed near the center of a spherically shaped mesh anode. In both systems, the ion current streaming through the mesh was measured by a biased collector. The mesh anodes had geometric transmittances of 60 percent and 72 percent, respectively, which were taken into account as correction factors. The ion current from different cathode materials was measured for 50-500 A of arc current. The ion current normalized by the arc current was found to depend on the cathode material, with values in the range from 5 percent to 19 percent. The normalized ion current is generally greater for elements of low cohesive energy. The ion erosion rates were determined from values of ion current and ion charge states, which were previously measured in the same ion source. The absolute ion erosion rates range from 16-173 mu g/C.

Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu; Savkin,Konstantin P.; Brown, Ian G.; Nikolaev, Alexey G.

2005-05-25T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

High-speed EDM milling with moving electric arcs  

Science Journals Connector (OSTI)

A novel high-speed electrical discharge machining (EDM) milling method using moving electric arcs has been proposed in this study. We connected a copper electrode rotating rapidly around its axis and a work piece to a DC power supply to generate a moving electric arc. To ensure high relative speed of any point on the electrode with respect to the work piece, the electrode was shaped like a pipe. It was observed that the electric arcs move rapidly within the discharge gap due to the revolution of the tool electrode, removing the materials on the electrode along the track of the arc roots. To explore the characteristics of machining with moving electric arcs, an EDM milling apparatus was devised. Two planes with approximately the same roughness were machined separately by this equipment and a traditional EDM machine for comparison. It was found that a much higher material removal rate can be easily achieved by EDM milling with moving electric arcs. In the meanwhile, wear of the tool electrode in this new method is negligible, which is greatly favorable for machining accuracy. The microstructures of these surfaces were also investigated for further information.

Fuzhu Han; Yongxain Wang; Ming Zhou

2009-01-01T23:59:59.000Z

162

Advanced RenewableEnergy Company ARC Energy | Open Energy Information  

Open Energy Info (EERE)

Advanced RenewableEnergy Company ARC Energy Advanced RenewableEnergy Company ARC Energy Jump to: navigation, search Name Advanced RenewableEnergy Company (ARC Energy) Place Nashua, New Hampshire Product New Hampshire-based stealth mode LED substrate manufacture equipment provider which aims to lower the cost of LEDs. Coordinates 42.758365°, -71.464209° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.758365,"lon":-71.464209,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

163

ArcSafe® with Pulsed Arrested Spark Discharge  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ArcSafe® ArcSafe® with Pulsed Arrested Spark Discharge  2007 R&D 100 Award Entry Form ArcSafe® with Pulsed Arrested Spark Discharge  Joint Submitters Submitting Organization Sandia National Laboratories PO Box 5800, MS 1181 Albuquerque, NM 87185-1181 USA Larry Schneider Phone: (505) 845-7135 Fax: (505) 845-7685 Email: lxschne@sandia.gov AFFIRMATION: I affirm that all information submitted as a part of, or supplemental to, this entry is a fair and accurate represen- tation of this product. (Signature)______________________________________ Astronics-Advanced Electronic Systems, Inc. 9845 Willows Rd NE City: Redmond State: WA Zip/Postal: 98052-2540 USA Contact Name: Michael Ballas, Program Manager Phone: (425) 895-4304 Fax: (425)702.4930 Email: michael.ballas@astronics.com

164

A Miocene Island-Arc Volcanic Seamount- The Takashibiyama Formation,  

Open Energy Info (EERE)

Island-Arc Volcanic Seamount- The Takashibiyama Formation, Island-Arc Volcanic Seamount- The Takashibiyama Formation, Shimane Peninsula, Sw Japan Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Miocene Island-Arc Volcanic Seamount- The Takashibiyama Formation, Shimane Peninsula, Sw Japan Details Activities (0) Areas (0) Regions (0) Abstract: The Miocene volcanic complex of the Takashibiyama Formation consists largely of subalkali, subaqueous basalt to andesite lavas and andesite to dacite subaqueous volcaniclastic flow deposits. Most of subaqueous lavas are moderately to intensely brecciated with rugged rough surfaces and ramp structures similar to subaerial block lava. Volcaniclastic flow deposits commonly include basalt to andesite lava fragments and/or pyroclastic materials, and are similar in internal

165

Measurement of total ion flux in vacuum Arc discharges  

SciTech Connect (OSTI)

A vacuum arc ion source was modified allowing us to collections from arc plasma streaming through an anode mesh. The mesh had ageometric transmittance of 60 percent, which was taken into account as acorrection factor. The ion current from twenty-two cathode materials wasmeasured at an arc current of 100 A. The ion current normalized by thearc current was found to depend on the cathode material, with valuesinthe range from 5 percent to 11 percent. The normalized ion current isgenerally greater for light elements than for heavy elements. The ionerosion rates were determined fromvalues of ion currentand ion chargestates, which were previously measured in the same experimental system.The ion erosion rates range from 12-94 mu g/C.

Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu.; Brown, Ian G.

2004-04-12T23:59:59.000Z

166

PNNL 331 Building Arc Flash Team Investigation Report  

SciTech Connect (OSTI)

On Friday, April 21, 2006, a PNNL electrician was performing repair of an electrical system for the 331 Building chilled water pump (CHWP) No.2, when an electrical arc flash occurred inside a 480V combination motor starter. The electrician was taken to the on-site medical provider for evaluation and was released for return to work without restriction. The electrician was not shocked, but did receive a minor, superficial (first degree) burn on the left wrist. This report, the result of a thorough review by the 331 Building Arc Flash Assessment Team, provides an in-depth look at the steps leading up to the arc-flash and recommendations and opportunities for improvement.

Deichman, Mark L.; Drewrey, John C.; Hodges, Hurtis; Madson, Vernon J.; Minton, Allen L.; Montgomery, Daniel M.; Olson, Marvin E.; Rojas, Pedro H.; Sanan, Sanjay K.; Sharp, Reed D.; Sparks, Bobby R.; Swearingen, Gary L.

2006-06-06T23:59:59.000Z

167

Multipass Arc Lattice Design for Recirculating Linac Muon Accelerators  

SciTech Connect (OSTI)

Recirculating linear accelerators (RLA) are the most likely means to achieve rapid acceleration of short-lived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. A drawback of this scheme is that a separate return arc is required for each passage of the muons through the linac. In the work described here, a novel arc optics based on a Non-Scaling Fixed Field Alternating Gradient (NSFFAG) lattice is developed, which would provide sufficient momentum acceptance to allow multiple passes (two or more consecutive energies) to be transported in one string of magnets. An RLA with significantly fewer arcs will reduce the cost. We will develop the optics and technical requirements to allow the maximum number of passes by using an adjustable path length to accurately control the returned beam to synchronize with the linac RF phase.

G.M. Wang, R.P. Johnson, S.A. Bogacz, D. Trbojevic

2009-05-01T23:59:59.000Z

168

Graphite electrode DC arc furnace. Innovative technology summary report  

SciTech Connect (OSTI)

The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of feed composition variations on process operating conditions and slag product performance; and collecting mass balance and operating data to support equipment and instrument design.

NONE

1999-05-01T23:59:59.000Z

169

Choreographing Couch and Collimator in Volumetric Modulated Arc Therapy  

SciTech Connect (OSTI)

Purpose: To design and optimize trajectory-based, noncoplanar subarcs for volumetric modulated arc therapy (VMAT) deliverable on both Varian TrueBEAM system and traditional accelerators; and to investigate their potential advantages for treating central nervous system (CNS) tumors. Methods and Materials: To guide the computerized selection of beam trajectories consisting of simultaneous couch, gantry, and collimator motion, a score function was implemented to estimate the geometric overlap between targets and organs at risk for each couch/gantry angle combination. An initial set of beam orientations is obtained as a function of couch and gantry angle, according to a minimum search of the score function excluding zones of collision. This set is grouped into multiple continuous and extended subarcs subject to mechanical limitations using a hierarchical clustering algorithm. After determination of couch/gantry trajectories, a principal component analysis finds the collimator angle at each beam orientation that minimizes residual target-organ at risk overlaps. An in-house VMAT optimization algorithm determines the optimal multileaf collimator position and monitor units for control points within each subarc. A retrospective study of 10 CNS patients compares the proposed method of VMAT trajectory with dynamic gantry, leaves, couch, and collimator motion (Tra-VMAT); a standard noncoplanar VMAT with no couch/collimator motion within subarcs (Std-VMAT); and noncoplanar intensity-modulated radiotherapy (IMRT) plans that were clinically used. Results: Tra-VMAT provided improved target dose conformality and lowered maximum dose to brainstem, optic nerves, and chiasm by 7.7%, 1.1%, 2.3%, and 1.7%, respectively, compared with Std-VMAT. Tra-VMAT provided higher planning target volume minimum dose and reduced maximum dose to chiasm, optic nerves, and cochlea by 6.2%, 1.3%, 6.3%, and 8.4%, respectively, and reduced cochlea mean dose by 8.7%, compared with IMRT. Tra-VMAT averaged beam-on time was comparable to Std-VMAT but significantly (45%) less than IMRT. Conclusion: Optimized couch, gantry, and collimator trajectories may be integrated into VMAT with improved mechanical flexibility and may provide better dosimetric properties and improved efficiency in the treatment of CNS tumors.

Yang Yingli [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zhang Pengpeng, E-mail: zhangp@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Happersett, Laura; Xiong Jianping; Yang Jie; Chan, Maria [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Beal, Kathryn [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Mageras, Gig; Hunt, Margie [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2011-07-15T23:59:59.000Z

170

E-Print Network 3.0 - arc deposition system Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in the Asir terrane, which was active between... erosion and deposition in the back-arc basin environment (Camp, 1984). Regional metamorphism in the WBMD... volcanic arc system. J....

171

ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education  

E-Print Network [OSTI]

1 ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education Case the ARCS Foundation Awards Luncheon in Atlanta on November 21, 2013. Application Materials: 1) A letter

Arnold, Jonathan

172

Evolution of residual stresses in micro-arc oxidation ceramic coatings on 6061 Al alloy  

Science Journals Connector (OSTI)

Most researches on micro-arc oxidation mainly focus on the application rather than ... dimensional stability and corrosion resistance, etc. The micro-arc oxidation ceramic coatings are produced on the surfaces .....

Dejiu Shen; Jingrui Cai; Changhong Guo…

2013-11-01T23:59:59.000Z

173

Comparative analysis of methods for ion-plasma sputter deposition and micro-arc oxidation  

Science Journals Connector (OSTI)

We describe the following advantages of micro-arc oxidation (MAO) over ion-plasma sputter deposition ... of operation by personnel. These advantages make micro-arc oxidation a promising technique for metallurgica...

M. V. Gerasimov

2007-11-01T23:59:59.000Z

174

Optimization of NH3 Decomposition by Control of Discharge Mode in a Rotating Arc  

Science Journals Connector (OSTI)

In this study, the characteristic behavior of a rotating arc was investigated. Various modes, depending on the electric power supplied, can be observed in a rotating arc. Each mode produces different discharge ch...

Dae Hoon Lee; Kwan-Tae Kim; Hee Seok Kang…

2014-01-01T23:59:59.000Z

175

Numerical computation of electric arc with annular attachment on the cathode butt end  

Science Journals Connector (OSTI)

The results of computing a stationary arc with annular attachment on the butt end of a solid cylindrical cathode are presented. The influence of the discharge external parameters on the characteristics of arc ...

A. Zh. Zhainakov; R. M. Urusov; T. E. Urusova

2006-12-01T23:59:59.000Z

176

Growth Conditions of Double-Walled Carbon Nanotubes in Arc Discharge  

Science Journals Connector (OSTI)

Growth Conditions of Double-Walled Carbon Nanotubes in Arc Discharge ... Preparation conditions for large-scale synthesis of double-walled carbon nanotubes (DWCNTs) by using electric arc discharge were examined. ...

Yahachi Saito; Takanori Nakahira; Sashiro Uemura

2003-01-04T23:59:59.000Z

177

Mechanism of current redistribution between jets in a double-jet electric arc  

Science Journals Connector (OSTI)

Characteristics of a double-jet electric arc have been determined by numerical simulation of ... plasma electrodes, along which the character of arc discharge changes from self-sustained to non-self-...

E. B. Kulumbaev; T. B. Nikulicheva

2013-01-01T23:59:59.000Z

178

Parameters of free-burning arc discharge plasma in air with silver-based electrodes  

Science Journals Connector (OSTI)

We have used optical spectroscopy to study the radial temperature profiles for an electric arc plasma between silver electrodes and electrodes made ... . We established that the parameters of the arc discharge pl...

I. L. Babich; A. N. Veklich; L. A. Kryachko…

2006-05-01T23:59:59.000Z

179

Dependence of thermal destabilization of electric-arc plasma in an air flow on discharge conditions  

Science Journals Connector (OSTI)

The effect of the conditions of electric-arc burning in an air flow on the ... processes in the development of instability in an arc-discharge column is shown.

V. N. Borisyuk; S. V. Goncharik…

1997-03-01T23:59:59.000Z

180

E-Print Network 3.0 - arc box test Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

box test Search Powered by Explorit Topic List Advanced Search Sample search results for: arc box test Page: << < 1 2 3 4 5 > >> 1 Fat arcs for implicitly defined curves Szilvia...

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

A static voltage-current characteristic for the low current DC arc  

E-Print Network [OSTI]

systems has failed to detect arcing faults numerous times with disastrous consequences. The fault leaves a charred furrow, known as the ''arc track'', through Kapton cable insulation. Tests by NASA and others have confirmed that the average circuit...

Moores, Gregory Lee

2012-06-07T23:59:59.000Z

182

E-Print Network 3.0 - arc protection class Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in a GIS: A Bidirectional Link between ArcView 2.0TM and XGobi Summary: . The XGobi remote proce- dures callable from within ArcView 2.0 can be grouped into two classes. One...

183

E-Print Network 3.0 - arc routing problem Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Sample search results for: arc routing problem Page: << < 1 2 3 4 5 > >> 1 GIS by ESRITM What is ArcGIS Summary: allocation) Solving complex routing problems Querying...

184

E-Print Network 3.0 - arc weld-surfacing process Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Electrical and Computer Engineering, University of Kentucky Collection: Engineering 3 GIS by ESRITM What is ArcGIS Summary: PlotTM, ArcEditTM, and so on). Geo- processing Map...

185

Development of a Plasma Arc Manufacturing Process and Machine to Create Metal Oxide Particles in Water From Wire Feedstock.  

E-Print Network [OSTI]

??A plasma arc erosion process can be used to create metal and metal oxide particles in the ultra-fine size range (<70 um). An electric arc… (more)

George, Jonathan Alan 1983-

2010-01-01T23:59:59.000Z

186

Effect of Micro Arc Oxidation Coatings on Corrosion Resistance of 6061-Al Alloy  

Science Journals Connector (OSTI)

In the present study, the corrosion behavior of micro arc oxidation (MAO) coatings deposited at two current...

Nitin P. Wasekar; A. Jyothirmayi…

2008-10-01T23:59:59.000Z

187

Cyclic Strength of Titanium Alloys, Anodized under Micro-Arc Conditions, in Sea Water  

Science Journals Connector (OSTI)

The durability of titanium alloys having undergone micro-arc oxidation and then exposed to sea water is...

G. A. Lavrushin; S. V. Gnedenkov; P. S. Gordienko…

2002-07-01T23:59:59.000Z

188

Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna  

SciTech Connect (OSTI)

RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Wooldridge, E. [EURATOM/CCFE Fusion Association, Culham Science Centre (United Kingdom)

2011-12-23T23:59:59.000Z

189

Electric Arc Locator in Photovoltaic Power Systems Using Advanced Signal Processing Techniques  

E-Print Network [OSTI]

in detecting the partial discharges associated with the production of an electric arc in a high voltage power in fault detection and localization. In [1] we have shown that electric arc (or partial dischargeElectric Arc Locator in Photovoltaic Power Systems Using Advanced Signal Processing Techniques

Paris-Sud XI, Université de

190

EDFA Gain Flattening Using Long-Period Fibre Gratings Based on the Electric Arc Technique  

E-Print Network [OSTI]

of new stresses during the electric arc discharges as the main mechanism for their formation [5]. #12EDFA Gain Flattening Using Long-Period Fibre Gratings Based on the Electric Arc Technique O. Frazão of the long-period fibre grating is based on the electric arc technique. 1. Introduction. The gain flattening

Haddadi, Hamed

191

Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 49  

E-Print Network [OSTI]

Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 49 CESAM-OPJ-GIS Document current as of March 28, 2012 10:27 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 49 CESAM

US Army Corps of Engineers

192

Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 50  

E-Print Network [OSTI]

Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 50 CESAM-OPJ-GIS Document current as of June 27, 2012 10:09 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 50 CESAM

US Army Corps of Engineers

193

The fractal nature of vacuum arc cathode spots  

SciTech Connect (OSTI)

Cathode spot phenomena show many features of fractals, for example self-similar patterns in the emitted light and arc erosion traces. Although there have been hints on the fractal nature of cathode spots in the literature, the fractal approach to spot interpretation is underutilized. In this work, a brief review of spot properties is given, touching the differences between spot type 1 (on cathodes surfaces with dielectric layers) and spot type 2 (on metallic, clean surfaces) as well as the known spot fragment or cell structure. The basic properties of self-similarity, power laws, random colored noise, and fractals are introduced. Several points of evidence for the fractal nature of spots are provided. Specifically power laws are identified as signature of fractal properties, such as spectral power of noisy arc parameters (ion current, arc voltage, etc) obtained by fast Fourier transform. It is shown that fractal properties can be observed down to the cutoff by measurement resolution or occurrence of elementary steps in physical processes. Random walk models of cathode spot motion are well established: they go asymptotically to Brownian motion for infinitesimal step width. The power spectrum of the arc voltage noise falls as 1/f {sup 2}, where f is frequency, supporting a fractal spot model associated with Brownian motion.

Anders, Andre

2005-05-27T23:59:59.000Z

194

Self-organisation Processes In The Carbon ARC For Nanosynthis  

SciTech Connect (OSTI)

The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

Ng, Jonathan; Raitses, Yevgeny

2014-02-26T23:59:59.000Z

195

Anode Sheath Switching in a Carbon Nanotube Arc Plasma  

SciTech Connect (OSTI)

The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.

Abe Fetterman, Yevgeny Raitses, and Michael Keidar

2008-04-08T23:59:59.000Z

196

A Distributed Arc-Consistency Algorithm T. Nguyen, Y. Deville  

E-Print Network [OSTI]

cient way of tackling constraint satisfaction problems (CSP). In particular, various arc and hardware design. Informally, a CSP is com- posed of a nite set of variables, each of which is taking values the variables can simultaneously take. Resolving a CSP consists in nding one or all complete assignments

Deville, Yves

197

A Generic ArcConsistency Algorithm and its Specializations 1  

E-Print Network [OSTI]

con­ straint satisfaction problems (CSP). In particular, various arc­consistency algorithms have been constraints) and d is the size of the largest domain. Being applicable to the whole class of (binary) CSP as constraint satisfaction problems (CSP). A CSP is defined by a finite set of variables taking values from

Deville, Yves

198

A Generic Arc-Consistency Algorithm and its Specializations1  

E-Print Network [OSTI]

satisfaction problems (CSP). In particular, various arc-consistency algorithms have been proposed, originating is the size of the largest domain. Being applicable to the whole class of (binary) CSP, these algorithms do satisfaction problems (CSP). A CSP is de ned by a nite set of variables taking values from nite domains

Deville, Yves

199

Generation of high charge state ions in vacuum arc ion sources by a ``current jump'' method  

SciTech Connect (OSTI)

In the investigation of ion charge state distributions (CSD) in vacuum arc plasmas, good correlation between increase in arc operating voltage and mean ion charge state has been established. Therefore, to increase the mean charge state of a vacuum arc plasma, it is necessary to find ways to increase the arc operating voltage. The voltage can be increased via transients associated with the arc current by means of which a rather high operation voltage can be established across the discharge gap. Experiments were performed both in Tomsk and Berkeley with the discharge system of a vacuum arc ion source. To effect a step current rise an additional power supply was connected to the usual vacuum arc supply. This power supply made it possible to increase the vacuum arc current up to 1 kA for several {micro}s. As a rule the current jump was produced after 100--200 {micro}s into the main discharge pulse when all principal parameters of the vacuum arc were already established. To measure the CSD a time-of-flight method was used. As followed from experiments, superposition of a short, high current pulse to the vacuum arc current pulse is accompanied by a jump in arc operation voltage. Subsequently during the current step the voltage falls exponentially to one hundred volts after the completion of the current jump, and the arc voltage takes its conventional value (20--40V). Because of this increase in arc operation voltage, an enhancement of high charge station ion fractions was observed. For example, with a Ti-cathode with conventional arc parameters there is only very small value to Ti{sup 4+} ion fraction in the vacuum arc plasma. Applying strong magnetic field increases the fraction of these ions up to 20% of the total beam current. The current jump enhanced this value up to 40%.

Bugaev, A.S.; Oks, E.M.; Yushkov, G.Y.; Brown, I.G.

1999-07-01T23:59:59.000Z

200

Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical Intra-oceanic Arc1  

E-Print Network [OSTI]

Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical at Dallas, Box 830688, Richardson, TX 75083-0688, USA A B S T R A C T Major element compositions of glass of these lavas reflects accumulation of plagioclase. Glass inclusions also show the common occurrence of felsic

Stern, Robert J.

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Stability analysis of multi-phase AC arc discharge for in-flight glass melting  

Science Journals Connector (OSTI)

A stable multi-phase AC arc was generated to by transformers at a commercial electric system. The arc discharge behavior and the stability were investigated by the high-speed video camera observation synchronized with the voltage waveform analysis. The effect of the number of phase and the flaming gas addition into the arc region on the arc behavior and the arc stability were studied. Results showed that the re-ignition occurred between adjacent electrodes periodically. Two kinds of the stability analysis methods were introduced. The estimated fluctuation degree showed that an increase of the number of the phase leads to the stable multi-phase AC arc. The deviation of the arc voltage from the average arc voltage was estimated to evaluate the uniformity of the multi-phase AC arc. Although an addition of the oxygen flame into the arc region leads to lower uniformity, the modification of the electrode position can improve the uniformity of the multi-phase AC arc.

Manabu Tanaka; Yosuke Tsuruoka; Yaping Liu; Tsugio Matsuura; Takayuki Watanabe

2011-01-01T23:59:59.000Z

202

Radiation in molecular dynamic simulations  

SciTech Connect (OSTI)

Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The new technique passes a key test: it relaxes to a blackbody spectrum for a plasma in local thermodynamic equilibrium. This new tool also provides a method for assessing the accuracy of energy and momentum exchange models in hot dense plasmas. As an example, we simulate the evolution of non-equilibrium electron, ion, and radiation temperatures for a hydrogen plasma using the new molecular dynamics simulation capability.

Glosli, J; Graziani, F; More, R; Murillo, M; Streitz, F; Surh, M

2008-10-13T23:59:59.000Z

203

MAGENCO: A map generalization controller for Arc/Info  

SciTech Connect (OSTI)

The Arc/Info GENERALIZE command implements the Douglas-Peucker algorithm, a well-regarded approach that preserves line ``character`` while reducing the number of points according to a tolerance parameter supplied by the user. The authors have developed an Arc Macro Language (AML) interface called MAGENCO that allows the user to browse workspaces, select a coverage, extract a sample from this coverage, then apply various tolerances to the sample. The results are shown in multiple display windows that are arranged around the original sample for quick visual comparison. The user may then return to the whole coverage and apply the chosen tolerance. They analyze the ergonomics of line simplification, explain the design (which includes an animated demonstration of the Douglas-Peucker algorithm), and discuss key points of the MAGENCO implementation.

Ganter, J.H.; Cashwell, J.W.

1994-06-01T23:59:59.000Z

204

A Systematic Search for High Surface Brightness Giant Arcs in a Sloan Digital Sky Survey Cluster Sample  

E-Print Network [OSTI]

We present the results of a search for gravitationally-lensed giant arcs conducted on a sample of 825 SDSS galaxy clusters. Both a visual inspection of the images and an automated search were performed and no arcs were found. This result is used to set an upper limit on the arc probability per cluster. We present selection functions for our survey, in the form of arc detection efficiency curves plotted as functions of arc parameters, both for the visual inspection and the automated search. The selection function is such that we are sensitive only to long, high surface brightness arcs with g-band surface brightness mu_g 10. Our upper limits on the arc probability are compatible with previous arc searches. Lastly, we report on a serendipitous discovery of a giant arc in the SDSS data, known inside the SDSS Collaboration as Hall's arc.

J. Estrada; J. Annis; H. T. Diehl; P. B. Hall; T. Las; H. Lin; M. Makler; K. W. Merritt; V. Scarpine; S. Allam; D. Tucker

2007-01-12T23:59:59.000Z

205

SCI-Arc/Caltech Solar Decathlon 2011 Project Manual  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

CHIP CHIP 2 011 SCI---ARC / C altech S olar D ecathlon 2 011 As---Built P roject M anual 1 D.O.E. S olar D ecathlon 2 011 U.S. DEPARTMENT OF ENERGY SOLAR DECATHLON 2011 Team SCI-Arc/Caltech CHIP COMPACT HYPER_INSULATED PROTOTYPE Project Manual August 11,2011 Project Manager (Design and Construction): Reed Finlay (reed_finlay@sciarc.edu) Project Manager (PR and Development): Elisabeth Neigert (elisabeth_neigert@sciarc.edu) CHIP 2 011 SCI---ARC / C altech S olar D ecathlon 2 011 As---Built P roject M anual 2 D.O.E. S olar D ecathlon 2 011 Table o f C ontents Summary o f C hanges 2 Rules C ompliance C hecklist 3 Structural C alculations 6 Detailed W ater B udget 7 Summary o f U nlisted E lectrical C omponents 9 Summary o f R econfigurable F eatures 10 Interconnection A pplication F orm 11 Energy A nalysis R esults a nd D iscussion

206

Vacuum Arc Ion Sources: Recent Developments and Applications  

SciTech Connect (OSTI)

The vacuum arc ion source has evolved over the past twenty years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface modification. Another important use is for injection of high current beams of heavy metal ions into the front ends of particle accelerators, and much excellent work has been carried out in recent years in optimizing the source for reliable accelerator application. The source also provides a valuable tool for the investigation of the fundamental plasma physics of vacuum arc plasma discharges. As the use of the source has grown and diversified, at the same time the ion source performance and operational characteristics have been improved in a variety of different ways also. Here we review the growth and status of vacuum arc ion sources around the world, and summarize some of the applications for which the sources have been used.

Brown, Ian; Oks, Efim

2005-05-01T23:59:59.000Z

207

A Glove Box Enclosed Gas-Tungsten Arc Welding System  

SciTech Connect (OSTI)

This report describes an inert atmosphere enclosed gas-tungsten arc welding system which has been assembled in support of the MC2730, MC2730A and MC 3500 Radioisotope Thermoelectric Generator (RTG) Enhanced Surveillance Program. One goal of this program is to fabricate welds with microstructures and impurity levels which are similar to production heat source welds previously produced at Los Alamos National Laboratory and the Mound Facility. These welds will subsequently be used for high temperature creep testing as part of the overall component lifetime assessment. In order to maximize the utility of the welding system, means for local control of the arc atmosphere have been incorporated and a wide range of welding environments can easily be evaluated. The gas-tungsten arc welding system used in the assembly is computer controlled, includes two-axis and rotary motion, and can be operated in either continuous or pulsed modes. The system can therefore be used for detailed research studies of welding impurity effects, development of prototype weld schedules, or to mimic a significant range of production-like welding conditions. Fixturing for fabrication of high temperature creep test samples have been designed and constructed, and weld schedules for grip-tab and test welds have been developed. The microstructure of these welds have been evaluated and are consistent with those used during RTG production.

Reevr, E, M; Robino, C.V.

1999-07-01T23:59:59.000Z

208

PV Analyst: Coupling ArcGIS with TRNSYS to assess distributed photovoltaic potential in urban areas  

Science Journals Connector (OSTI)

This study presents a means to extend the functionality of Geographic Information Systems (GIS) in assessing distributed photovoltaic (PV) potential in urban areas, via the new ArcGIS extension: PV Analyst. A methodology is proposed for coupling ArcGIS with TRNSYS that enables the PV Analyst extension to use the capabilities of 4 and 5-parameter PV array performance models and the irradiance components in TRNSYS for solar energy simulations in geospatial contexts. Because PV Analyst is embedded within the ArcMap environment, part of ArcGIS software package, the strong capabilities of ArcGIS and other ArcGIS extensions such as 3D Analyst, Spatial Analyst and Tracking Analyst can be fully utilized with PV Analyst’s functionalities. This paper describes the concept and details of the extension development, as well as its application to the Pollock Commons area at the Pennsylvania State University.

Yosoon Choi; Jeffrey Rayl; Charith Tammineedi; Jeffrey R.S. Brownson

2011-01-01T23:59:59.000Z

209

Diameters of Single-Wall Carbon Nanotubes Depending on Helium Gas Pressure in an Arc Discharge  

Science Journals Connector (OSTI)

Diameters of Single-Wall Carbon Nanotubes Depending on Helium Gas Pressure in an Arc Discharge ... So far, relatively large quantities of SWNTs have been produced by using Y?Ni and Fe?Ni catalysts for the electric arc discharge method28-30 and by using a Co?Ni catalyst for the pulsed laser ablation method. ... The electric current of the arc discharge also affected the yield of SWNTs though its effect was not as serious as the helium pressure. ...

Yahachi Saito; Yoshihiko Tani; Atsuo Kasuya

2000-02-26T23:59:59.000Z

210

The characteristics of arcing faults in 480-volt power distribution systems  

E-Print Network [OSTI]

spontaneous arc-over to ground or to another phase. ~ Insulation failure due to surface conduction across conductive dust or contamination, or due to a cracked insulator body. ~ Conductive gases emanating from circuit breakers or fuses during circuit.... ~ Rodents or vermin, especially those returning from a wet outing to the warmth of the equipment. In tropical climates, snakes are known to have caused arcing faults across insulator strings. Since causes of arcing fault cannot always be eliminated in 480...

Shih, Yu?

2012-06-07T23:59:59.000Z

211

Tailored Distribution of Single-Wall Carbon Nanotubes from Arc Plasma Synthesis Using Magnetic Fields  

Science Journals Connector (OSTI)

We would like to acknowledge PPPL Offsite Research Program supported by the Office of Fusion Energy Sciences for supporting arc experiments. ...

Olga Volotskova; Jeffrey A. Fagan; Ji Yeon Huh; Frederick R. Phelan Jr.; Alexey Shashurin; Michael Keidar

2010-08-13T23:59:59.000Z

212

Effect of a floating electrode on an atmospheric-pressure non-thermal arc discharge  

Science Journals Connector (OSTI)

Characteristics of the atmospheric non-thermal ac arc air plasmas produced by a plasma generator with a floating electrode are investigated. The measurements show that with the help of the surface dielectric barrier discharges between the main electrodes and the floating electrode the ignition voltage of the non-thermal arc discharges can be reduced significantly and an arc discharge mode can be stabilized at high gas flow rates. The measuredtemperatures of the non-thermal arcs are at the level of 2000–3000 K under different operating conditions.

Zhi-Bin Wang; Guo-Xu Chen; Zhe Wang; Nan Ge; He-Ping Li; Cheng-Yu Bao

2011-01-01T23:59:59.000Z

213

E-Print Network 3.0 - arc geothermal systems Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for the Next 50 Years," EPRI ER-611-SR, Palo Alto, Ca.. ESRI: Using Arc... Utilized For District Heating Systems in Turkey," New Zealand ... Source: Stanford University -...

214

E-Print Network 3.0 - arc swedish section Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

arc swedish section Page: << < 1 2 3 4 5 > >> 1 Brita Bergman (born 303 1946) CURRICULUM VITAE 2011 Sign Language Section, Department of Linguistics Abridged version Summary:...

215

ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education  

E-Print Network [OSTI]

ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education Case Foundation Awards Luncheon in Atlanta on November 20, 2014. #12;Application Materials: 1) A letter

Arnold, Jonathan

216

A tool-path generation strategy for wire and arc additive manufacturing  

Science Journals Connector (OSTI)

This paper presents an algorithm to automatically generate optimal tool-paths for the wire and arc additive manufacturing (WAAM) process for a large class...

Donghong Ding; Zengxi (Stephen) Pan…

2014-07-01T23:59:59.000Z

217

Formation of micro-arc coatings on the surface of D16 aluminum alloy  

Science Journals Connector (OSTI)

Results of a study of how optically black coatings are formed by micro-arc oxidation on the surface of D16 aluminum alloy...

Zh. I. Bespalova; I. N. Panenko

2013-05-01T23:59:59.000Z

218

E-Print Network 3.0 - arc furnace dust Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Collection: Renewable Energy 2 The Effec' of Furnace Design and Operation on Air Pollution Summary: chemical constituents in furnace gases arc very malodorous, or toxic, when...

219

E-Print Network 3.0 - arc plasma furnace Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

PLASMA PHYSICS AND ENGINEERING Summary: replace costly traditional technologies as incineration and conventional plasma arc furnaces, and provide... ASSOCIATED LABORATORY ON...

220

E-Print Network 3.0 - arc consistency revisited Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

University of Singapore Collection: Computer Technologies and Information Sciences 3 GIS by ESRITM What is ArcGIS Summary: is an integrated geographic information system (GIS)...

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Measuring the pressure in ultrahigh-pressure mercury arcs  

SciTech Connect (OSTI)

Ultrahigh-pressure (UHP) mercury lamps are important as high-brightness light sources for digital projection. Hg pressures are usually above 20 MPa and difficult to measure. We have built special UHP lamps with a liquid Hg condensate in a temperature-controlled reservoir, allowing us to tune the Hg vapor pressure p between 14 and 30 MPa. As a simple measure for p, we recorded the width DELTAlambda of the 546 nm Hg line while varying p and also the lamp current I and voltage U. The data define a function p(DELTAlambda,I,U) that will deliver p to better than 3% from simple measurements of DELTAlambda, I, and U for most UHP lamps in the important 100-200 W power range. The method is applied to sample lamps, yielding pressures up to 26 MPa and demonstrating how filled Hg amount, burning position, arc gap, and lamp power affect the pressure. The effective temperature of typical UHP lamps is found to be 2400 K. We also derive an improved characteristic U(d,p,I) for the dependence of the arc voltage on arc gap, pressure, and current for electrode-stabilized Hg discharges in the UHP regime. Some aspects of the experiment are of general interest in the field of discharge lamps, such as a model for the heat balance of the Hg condensate under conductive, radiative, and evaporative cooling/heating, a short discussion of high-temperature vapor-pressure data for Hg, and an improved Hg equation of state for UHP conditions.

Hechtfischer, U.; Engelbrecht, B.; Carpaij, M.; Fischer, E.; Koerber, A. [Philips Research Laboratories, Weisshausstrasse 2, 52066 Aachen (Germany)

2009-09-01T23:59:59.000Z

222

Heat Recovery From Arc Furnaces Using Water Cooled Panels  

E-Print Network [OSTI]

to maintain a constant cooling water supply temperature in the cold well. The cooling tower fans can be manually reversed on slow speed for de-icing the cooling tower in winter to remove ice buildup on the slats. Level controller LL-2 shuts down pumps PI...HEAT RECOVERY FROM ARC FURNACES USING WATER COOLED PANELS D. F. Darby Deere & Company Moline, Illinois ABSTRACT In 1980-81, the John Deere Foundry at East Moline underwent an expansion program that in creased its capacity by over 60...

Darby, D. F.

223

Shunting arc plasma source for pure carbon ion beam  

SciTech Connect (OSTI)

A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y. [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

2012-02-15T23:59:59.000Z

224

Rifting of the Izu-Bonin arc in the Quaternary and Mid-Oligocene  

SciTech Connect (OSTI)

Eruption of middle Eocene-lower Oligocene boninites and island arc tholeiites created the 200 km wide Izu-Bonin arc massif following the initiation of subduction {approximately}50 Ma. Mid-Oligocene rifting formed a 40-70 km wide forearc basin between the Eocene outer-arc high and the Eo-Oligocene arc (now the frontal arc high), with maximum extension at the latitudes of the Bonin Ridge and Trough. The Oligocene forearc basin was rapidly (100-300 m/m.y.) filled with turbidite and debris flow deposits produced by concurrent volcanism and erosion of the surrounding highs. Contemporaneous stretching in the backarc region produced dominantly east-dipping, NNE-trending, normal faults and culminated in backarc spreading in the Shikoku basin (25-15 Ma), isolating the Palau-Kyushu remnant arc. The forearc and remnant arc sediments record a dearth of volcanogenic input between 23 and 17 Ma; evidence that an arc volcanic minimum accompanied backarc spreading. The middle Miocene to Recent volcanic front formed 0(S)-50(N) km west of the Oligocene arc and has loaded and flexed the forearc. Further west, chains of submarine volcanoes erupted along the extension of Shikoku basin fracture zones. Basaltic sills were emplaced in the forearc. Explosive volcanism from rhyolitic calderas has increased dramatically since the late Pliocene, especially in the last 0.2 Ma. Since {approximately}2 Ma the arc has been stretched again, producing rapidly subsiding (300-2,250 m/m.y.) graben, immediately west of the volcanic front, which are segmented along strike by oblique transfer zones. The Sumisu Rift is partially filled with (<1.5 Ma) volcaniclastic turbidites and hemipelagic sediments and is intruded by backarc basin basalts. About 1 km of syn-rift uplift of the arc margin footwall has produced an unconformity, beneath surficial pumice, that extends back to pumiceous sediments >2.35 Ma.

Taylor, B. (Univ. of Hawaii, Honolulu (USA))

1990-06-01T23:59:59.000Z

225

Advanced Resin Cleaning System (ARCS) at Grand Gulf Nuclear Station  

SciTech Connect (OSTI)

Steam generation system in-core components can undergo serious material degradation by a variety of corrosion-related phenomena. These phenomena are largely controlled by boiler water (i.e. reactor water) chemistry which is strongly impacted by the performance of the condensate system mixed bed ion exchange units. In Boiling Water Reactors (BWR), the mixed bed ion exchange units not only provide protection from ionic contaminants, but also remove insoluble corrosion products by filtration/adsorption. These insoluble corrosion products removed by the ion exchange units must then be periodically cleaned from the resin bed by some process external to the BWR primary water loop. A unique resin cleaning process called the {open_quotes}Advanced Resin Cleaning System{close_quotes} (ARCS) was developed in the late 1980`s by members of CENTEC-XXI, located in Santa Clara, CA. This system, which has been successfully operated for several years at a Pressurized Water Reactor is highly efficient for removal of both insoluble corrosion products and anion/cation resin fines, and generates significantly less waste water than other cleaning methods. The ARCS was considered the most attractive method for meeting the demanding and costly resin cleaning needs of a BWR. A {open_quotes}Tailored Collaboration{close_quotes} project was initiated between EPRI, Entergy Operations (Grand Gulf Station), and CENTEC-XXI to demonstrate the {open_quotes}Advanced Resin Cleaning System{close_quotes} in a BWR.

Asay, R.H.; Earls, J.E.; Naughton, M.D. [Centec 21, Inc., Santa Clara, CA (United States)

1996-10-01T23:59:59.000Z

226

Spatial and time-dependent distribution of plasma parameters in the metal-halide arc lamp.  

E-Print Network [OSTI]

Spatial and time-dependent distribution of plasma parameters in the metal-halide arc lamp. A. Khakhaev, L. Luizova, K. Ekimov and A. Soloviev Petrozavodsk State University, Russia The metal-halide arc lamp is an effective light source and its investigation has a long history, but even at present some

Paris-Sud XI, Université de

227

The effects of micro arc oxidation of gamma titanium aluminide surfaces on osteoblast adhesion and differentiation  

Science Journals Connector (OSTI)

The adhesion and proliferation of human fetal osteoblasts, hFOB 1.19, on micro arc oxidized (MAO) gamma titanium aluminide (?TiAl ... 6Al-4V disks to study the effect of micro arc oxidation and glass coverslips a...

Pricilla Santiago-Medina; Paul A. Sundaram…

2014-06-01T23:59:59.000Z

228

Visible Light Emissions during Gas Tungsten Arc Welding and Its Application to Weld  

E-Print Network [OSTI]

\\ Visible Light Emissions during Gas Tungsten· Arc Welding and Its Application to Weld Image. EAGAR ABSTRACT. An experimental study was carried out to map the light emissions from a gas tungsten arc. The emissions were found to be dramat- ically different with different shielding gases, welding current and base

Eagar, Thomas W.

229

Spectroscopy of atmospheric pressure air jet plasma in transverse arc discharge Valeriy Chernyak1  

E-Print Network [OSTI]

Spectroscopy of atmospheric pressure air jet plasma in transverse arc discharge Valeriy Chernyak1 of the atmospheric pressure air jet plasma in the transverse cw dc arc discharge of high voltage was done. Within.g. application of approximation of the optically thin plasma in conditions of high atmospheric pressure

Paris-Sud XI, Université de

230

Cold-hollow-cathode arc discharge in crossed electric and magnetic fields  

Science Journals Connector (OSTI)

A crossed-field cold-hollow-cathode arc is stable at low working gas pressures...?2–10?1 Pa, magnetic-field-and gas-dependent arcing voltages of 20–50 V, and discharge currents of 20–200 A. This is ... produced o...

P. M. Schanin; N. N. Koval; Yu. Kh. Akhmadeev; S. V. Grigoriev

2004-05-01T23:59:59.000Z

231

Thermodynamics and Kinetics Analysis of Gasoline Reforming Assisted by Arc Discharge  

Science Journals Connector (OSTI)

Thermodynamics and Kinetics Analysis of Gasoline Reforming Assisted by Arc Discharge ... In the first one, the electric discharge is accounted for as a homogeneous energy source inside the whole reactor. ... kinetic schemes, without inclusion of specific plasma processes, is sufficient for simulation of H prodn. in discharges with hot plasmas, in particular, in low-current arc discharges. ...

Jean-Damien Rollier; Guillaume Petitpas; José Gonzalez-Aguilar; Adeline Darmon; Laurent Fulcheri; Rudolf Metkemeijer

2008-04-18T23:59:59.000Z

232

Synthesis of High Quality Single-Walled Carbon Nanotube Silks by the Arc Discharge Technique  

Science Journals Connector (OSTI)

Synthesis of High Quality Single-Walled Carbon Nanotube Silks by the Arc Discharge Technique ... Cerium was found to be a good element for stabilizing the electric arc, though the SWNT products as-grown from Ce had a low purity. ...

Hong-wei Zhu; Bin Jiang; Cai-lu Xu; De-hai Wu

2003-06-17T23:59:59.000Z

233

Optimal Location of Compressed Natural Gas (CNG) Refueling Station Using the Arc Demand Coverage Model  

Science Journals Connector (OSTI)

In this paper a model that locates Compressed Natural Gas (CNG) refueling stations to cover the full volume of vehicle flows is developed and applied. The model inputs consist of a road network include nodes and arcs, the volume of vehicle flows between ... Keywords: Compressed Natural Gas, Arc Demand Coverage Model, Optimal Location, Network

Abtin Boostani; Reza Ghodsi; Ali Kamali Miab

2010-05-01T23:59:59.000Z

234

Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc  

E-Print Network [OSTI]

Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein processes. Infusions of the -adrenoreceptor agonist, clen- buterol, into the BLA immediately after training increased Arc protein levels in the dorsal hippocampus. Additionally, posttraining intra-BLA infusions

O'Toole, Alice J.

235

Oxygen and Nitroaen Contamination During Submerged Arc Wel ding of Titanium  

E-Print Network [OSTI]

) ) ) ··- -~ Oxygen and Nitroaen Contamination During Submerged Arc Wel ding of Titanium T· \\v· Eagar* The oxygen content of ti tanium submerged arc wel ~ metal is primaril y derendent uron the purity of the fluo1~ ide fluxes, but it is shown here that the oxygen content of the weld metal may be affected

Eagar, Thomas W.

236

Development of the temperature fields in an electric arc struck on a point electrode in a homogeneous gas stream  

Science Journals Connector (OSTI)

A study is made of the problem of a point electric source in a homogeneous gas stream and operating in the arc discharge regime. The development of an electric arc struck on a point cathode in a ... . The station...

A. B. Vatazhin

237

Thermal motion of carbon clusters and production of carbon nanotubes by gravity-free arc discharge  

SciTech Connect (OSTI)

Thermal and diffusion properties of hot gas around a dc arc discharge under a gravity-free condition are investigated using a jet plane in order to improve the arc production of carbon clusters. Spherically symmetric temperature distribution of He gas around the arc plasma and monotonic slow expansion of the high-temperature region are observed. By means of the passive-type Mie scattering method, random slow diffusion of carbon clusters around the arc plasma is clearly observed under the gravity-free condition. This indicates that carbon clusters including single-walled carbon nanotubes are synthesized around the arc plasma where the He temperature is higher than 1000 K. It is confirmed that large bundles of fatter single-walled carbon nanotubes are produced under the gravity-free condition.

Mieno, T.; Takeguchi, M. [Department of Physics, Shizuoka University, Ooya, Suruga-ku, Shizuoka 422-8529 (Japan); National Institute for Material Science, Sakura, Tsukuba 305-0003 (Japan)

2006-05-15T23:59:59.000Z

238

ARC Meeting: 12/9/2012 Present: Pushpa, Ed, Malvika, Meng Shuen, Julia, Matt Voss, Sandhya, Connor, VLS, Adam,  

E-Print Network [OSTI]

(academic vs. research vs. other electives)? Connor: Want to find out across major Pushpa: ARC would like

Low, Steven H.

239

Effect of micro-arc oxidation surface modification on the properties of the NiTi shape memory alloy  

Science Journals Connector (OSTI)

In this paper, the effects of micro-arc oxidation (MAO) surface modification (alumina coatings)...P < 0.05).

J. L. Xu; Z. C. Zhong; D. Z. Yu; F. Liu…

2012-12-01T23:59:59.000Z

240

Modelling Of Magnetic Channels For Micro-droplets Filtering And Tests Of Their Efficiency In UHV Arc-discharges  

E-Print Network [OSTI]

Modelling Of Magnetic Channels For Micro-droplets Filtering And Tests Of Their Efficiency In UHV Arc-discharges

Strzyzewski, P; Mirowski, R; Sadowski, M; Tazzari, S; Witkowski, J

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Fabrication of Atomic-Scale Structures on Si(001) Surfaces  

Science Journals Connector (OSTI)

...1952), pp. 154-161; C. E. Weaver, Clays, Muds and Shales (Elsevier, Amsterdam, 1989). 30. W. A. DiMichele and...suggests that substrates or ultrathin films that have an anisotropic surface struc-ture consisting of well-separated groupings...

C. T. Salling; M. G. Lagally

1994-07-22T23:59:59.000Z

242

Atomic-scale Structural Characterizations of Functional Epitaxial Thin Films  

E-Print Network [OSTI]

......................................................................................................... 28 Figure 1.13. HR-STEM micrograph of Graphene (a) before83 and (b) after84 probe CS-correction. ............................................................................................ 29 Figure 2.1. Schematic diagram of the pulsed laser...

Zhu, Yuanyuan

2013-06-03T23:59:59.000Z

243

Atomic-Scale Assembly of a Heterogeneous Catalytic Site. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Instruments: Variable Temperature Scanning Probe Microscope Tags: ultra-high vacuum UHV VT SPM atomic-resolution imaging Volume: 129 Issue: 46 Pages: 14355-14361 Publication...

244

Lateral vibration effects in atomic-scale friction  

SciTech Connect (OSTI)

The influence of lateral vibrations on the stick-slip motion of a nanotip elastically pulled on a flat crystal surface is studied by atomic force microscopy measurements on a NaCl(001) surface in ultra-high vacuum. The slippage of the nanotip across the crystal lattice is anticipated at increasing driving amplitude, similarly to what is observed in presence of normal vibrations. This lowers the average friction force, as explained by the Prandtl-Tomlinson model with lateral vibrations superimposed at finite temperature. Nevertheless, the peak values of the lateral force, and the total energy losses, are expected to increase with the excitation amplitude, which may limit the practical relevance of this effect.

Roth, R. [Climate and Environment Physics, Physics Institute, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Fajardo, O. Y.; Mazo, J. J. [Departamento de Física de la Materia Condensada and Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, 50009 Zaragoza (Spain); Meyer, E. [Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland); Gnecco, E. [Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, 28049 Madrid (Spain)

2014-02-24T23:59:59.000Z

245

Measurement of Transient Atomic-scale Displacements in Thin Films...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The inset shows a streak camera measurement of the x-ray pulse duration. Ultrafast x-ray diffraction techniques typically utilize synchronized laser pulses as a trigger with...

246

Plasma Chemistry and Plasma Processing, Vol. 12, No.4, 1992 Infrared Radiation from an Arc Plasma and Its  

E-Print Network [OSTI]

of an atmospheric-pressure arc plasma are described from the viewpoint of continuorts radiation tlieory of the atmospheric arc plasma column is very sensitive to the electron density in the near infrared frequency rangeB ) Plasma Chemistry and Plasma Processing, Vol. 12, No.4, 1992 Infrared Radiation from an Arc

Eagar, Thomas W.

247

Comparative study of gel-based separated arc-discharge, HiPCO, and CoMoCAT carbon nanotubes  

E-Print Network [OSTI]

Nano Res 1 Comparative study of gel-based separated arc-discharge, HiPCO, and CoMoCAT carbon) Comparative Study of Gel-based Separated Arc-discharge, HiPCO, and CoMoCAT Carbon Nanotubes kinds of mainstream carbon nanotubes (arc-discharge, HiPCO, CoMoCAT) separated using low-cost gel

Zhou, Chongwu

248

Electroreduction of Oxygen in Polymer Electrolyte Fuel Cells by Activated Carbon Coated Cobalt Nanocrystallites Produced by Electric Arc Discharge  

Science Journals Connector (OSTI)

Electroreduction of Oxygen in Polymer Electrolyte Fuel Cells by Activated Carbon Coated Cobalt Nanocrystallites Produced by Electric Arc Discharge ... A recent review of the encapsulation of rare earth and iron group metals (Fe, Co, Ni) using electric arc discharge has been published by Saito. ... Nanotubes have been observed after activation of catalytically inactive carbon-coated Co nanocrystallites generated by electric arc discharge. ...

G. Lalande; D. Guay; J. P. Dodelet; S. A. Majetich; M. E. McHenry

1997-03-18T23:59:59.000Z

249

Presented in Concord, Merrimack and West Lebanon, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Fall 2012  

E-Print Network [OSTI]

Drivers Permit 10 1-day, 9am to 4pm To be announced Topics covered: ArcGIS 10 Exploring GIS maps Basic GIS Lebanon, NH December 4-6, Merrimack, NH Topics covered: ArcGIS 10 Creating GIS maps GIS techniques GIS and applications, participants learn how to use ArcGIS 10 to produce effective maps, edit and create GIS data

New Hampshire, University of

250

Design study for wire and arc additive manufacture  

Science Journals Connector (OSTI)

Additive Manufacture (AM) is a technique whereby freeform structures are produced by building up material in a layer by layer fashion. Among the different AM processes, Wire and Arc Additive Manufacture (WAAM) has the ability to manufacture large custom-made metal workpiece with high efficiency. A design study has been performed to explore the process capabilities of fabricating complicated geometries using WAAM. Features such as enclosed structures, crossing structures, and balanced building structures have been investigated in this study. Finite Element (FE) models are employed to take the thermo-mechanical performance into account. Robot tool path design has been performed to transfer the WAAM component designs into real components efficiently. This paper covers these essential design steps from a technical as well as practical point of view.

Jörn Mehnen; Jialuo Ding; Helen Lockett; Panos Kazanas

2014-01-01T23:59:59.000Z

251

Method of operating a centrifugal plasma arc furnace  

DOE Patents [OSTI]

A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 3}. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs.

Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

1998-03-24T23:59:59.000Z

252

Method of operating a centrifugal plasma arc furnace  

DOE Patents [OSTI]

A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe.sub.3 O.sub.4. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe.sub.2 O.sub.3. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater.

Kujawa, Stephan T. (Butte, MT); Battleson, Daniel M. (Butte, MT); Rademacher, Jr., Edward L. (Butte, MT); Cashell, Patrick V. (Butte, MT); Filius, Krag D. (Butte, MT); Flannery, Philip A. (Ramsey, MT); Whitworth, Clarence G. (Butte, MT)

1998-01-01T23:59:59.000Z

253

Arc discharge regulation of a megawatt hot cathode bucket ion source for the experimental advanced superconducting tokamak neutral beam injector  

SciTech Connect (OSTI)

Arc discharge of a hot cathode bucket ion source tends to be unstable what attributes to the filament self-heating and energetic electrons backstreaming from the accelerator. A regulation method, which based on the ion density measurement by a Langmuir probe, is employed for stable arc discharge operation and long pulse ion beam generation. Long pulse arc discharge of 100 s is obtained based on this regulation method of arc power. It establishes a foundation for the long pulse arc discharge of a megawatt ion source, which will be utilized a high power neutral beam injection device.

Xie Yahong; Hu Chundong; Liu Sheng; Jiang Caichao; Li Jun; Liang Lizhen [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Collaboration: NBI Team

2012-01-15T23:59:59.000Z

254

What we know and what we do not know about plasma arc cutting  

Science Journals Connector (OSTI)

After a brief history of plasma arc cutting (PAC) is given, its types and abilities are discussed. Experimental data (unfortunately, little is available) on plasma parameters are reviewed. The status of contemporary understanding of the process involved in PAC is presented. The main emphasis is on those processes that determine the technological abilities of the method. Along with the existing theories reviewed, we propose qualitative hypotheses on some of these processes. Among them are: dependence of the cyclic cathode erosion on the rate of current increase, double arcing and the role of insulating inclusions at the nozzle orifice on double arcing, dross formation and the shape of the kerf.

V A Nemchinsky; W S Severance

2006-01-01T23:59:59.000Z

255

Arc Detection and Interlock Module for the PEP II Low Level RF System  

SciTech Connect (OSTI)

A new arc detection and interlock generating module for the SLAC PEP-II low-level RF VXI-based system has been developed. The system is required to turn off the RF drive and high voltage power supply in the event of arcing in the cavity windows, klystron window, or circulator. Infrared photodiodes receive arc signals through radiation resistant optical fibers. Gain and bandwidth are selectable for each channel to allow tailoring response. The module also responds to interlock requests from other modules in the VXI system and communicates with the programmable logic controller (PLC) responsible for much of the low-level RF system's interlock functionality.

Tighe, R.; /SLAC

2011-08-31T23:59:59.000Z

256

A comparative numerical study of hybrid-stabilized argon–water electric arc  

Science Journals Connector (OSTI)

The paper presents numerical simulations of the discharge and the near-outlet regions of the hybrid-stabilized argon–water electric arc. Two different numerical methods for solving the set of conservative equations for the continuity, momentum and energy have been applied. The major difference between the results using the two methods occurs in the temperature distribution in arc fringes within the discharge chamber. This fact influences the potential drop, overpressure, reabsorption of radiation and arc efficiency. It is shown that the radial profiles of temperature at the exit nozzle are less influenced by different temperature distribution within the discharge chamber. Comparison with chosen experimental temperature profiles shows very good agreement.

Ji?í Jeništa; Hidemasa Takana; Hideya Nishiyama; Milada Bartlová; Vladimír Aubrecht; Petr K?enek; Viktor Sember; Alan Mašláni

2011-01-01T23:59:59.000Z

257

Modeling And Measurements Of The Arc Plasma In A Mixture Of Gases  

SciTech Connect (OSTI)

Radial distributions of Ar mass fractions and temperatures in plasmas produced in a wall-stabilized arc have been calculated. Modeling have been performed for many different mixtures of Ar+N2 and three different arc currents. The obtained results show that the radial distributions of Ar mass fractions strongly depend on the chemical composition of the plasma. In plasmas containing large amount of Ar the distributions have local minima at the arc axis (in high temperature plasma regions), whereas in plasmas consisting mainly of nitrogen the distributions reveal maxima on the discharge axis. Those features seem to be connected with the dissociation of the nitrogen.

Pawelec, E.; KsiaPzek, I. [University of Opole, Oleska 48, Opole (Poland)

2006-01-15T23:59:59.000Z

258

Technical manual, redesigned ARC-2A automatic radon counter. Final report  

SciTech Connect (OSTI)

The ARC-2A Automatic Radon Counter (Serial No. 87003) was manufactured in 1987 by Ocean Communication Systems, Inc, Panama City, Florida. It was designed as a stand-alone system, but was consistently plagued with problems. The manufacturer could not repair the machine. The ARC-2A was completely redesigned at NCCOSC RDT and E Division. It is now interfaced to a computer. A new manual was written with updated information and user instructions. The ARC-2A is an integral part of ongoing electro-optic propagation studies.... Radon, Electro-optics, Aerosol.

Littfin, K.M.

1992-09-01T23:59:59.000Z

259

Accelerated molecular dynamics and equation-free methods for simulating diffusion in solids.  

SciTech Connect (OSTI)

Many of the most important and hardest-to-solve problems related to the synthesis, performance, and aging of materials involve diffusion through the material or along surfaces and interfaces. These diffusion processes are driven by motions at the atomic scale, but traditional atomistic simulation methods such as molecular dynamics are limited to very short timescales on the order of the atomic vibration period (less than a picosecond), while macroscale diffusion takes place over timescales many orders of magnitude larger. We have completed an LDRD project with the goal of developing and implementing new simulation tools to overcome this timescale problem. In particular, we have focused on two main classes of methods: accelerated molecular dynamics methods that seek to extend the timescale attainable in atomistic simulations, and so-called 'equation-free' methods that combine a fine scale atomistic description of a system with a slower, coarse scale description in order to project the system forward over long times.

Deng, Jie; Zimmerman, Jonathan A.; Thompson, Aidan Patrick; Brown, William Michael (Oak Ridge National Laboratories, Oak Ridge, TN); Plimpton, Steven James; Zhou, Xiao Wang; Wagner, Gregory John; Erickson, Lindsay Crowl

2011-09-01T23:59:59.000Z

260

Mantle dynamics beneath the Pacific Northwest and the generation of voluminous back-arc volcanism  

E-Print Network [OSTI]

The Pacific Northwest (PNW) has a complex tectonic history and over the past ~17 Ma has played host to several major episodes of intraplate volcanism. These events include the Steens/Columbia River flood basalts (CRB) and ...

Long, Maureen D.

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc  

Open Energy Info (EERE)

238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc Details Activities (0) Areas (0) Regions (0) Abstract: Activities of 238U decay series radioisotopes have been determined for both postcaldera basalts erupted between 1849 and 1974 and genetically related young precaldera dacites from Batur volcano, Bali, Sunda arc. All rocks possess (230Th/238U) = 1 within 2 sigma error indicating that little, if any, fractionation between Th and U occurred during their genesis, or in their source regions, within approximately the last 350 ka. Both the basaltic and the dacitic rocks possess (230Th/232U) ~

262

An Archean Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine  

Open Energy Info (EERE)

Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Group, Abitibi Greenstone Belt, Canada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Archean Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Group, Abitibi Greenstone Belt, Canada Details Activities (0) Areas (0) Regions (0) Abstract: The 2730-Ma-old Hunter Mine Group (HMG), a dominantly felsic subaqueous volcanic sequence, was formed during early arc construction in the Abitibi greenstone belt (Quebec, Canada). The western part of the HMG contains a felsic dyke swarm up to 1.5 km wide and traceable up-section for 2.5 km. Five distinct generations were identified: (1) aphanitic to feldspar-phyric dykes; (2) quartz-feldspar-phyric dykes with < 5% quartz

263

Surface Modification of Smectite Clay Induced by Non-thermal Gliding Arc Plasma at Atmospheric Pressure  

Science Journals Connector (OSTI)

Smectite clay from Sabga (west-Cameroon) was treated in aqueous suspension by gliding arc plasma to modify its surface properties. The evolution of the modifications was followed with the exposure time and pos...

Antoine Tiya Djowe; Samuel Laminsi…

2013-08-01T23:59:59.000Z

264

The Consumption of Carbon in the Electric Arc. No. III. The Anode Loss  

Science Journals Connector (OSTI)

1 February 1916 research-article The Consumption of Carbon in the Electric Arc. No. III. The Anode Loss W. G. Duffield Mary D. Waller The Royal Society is collaborating with...

1916-01-01T23:59:59.000Z

265

Exhaust-gas measurements from NASAs HYMETS arc jet.  

SciTech Connect (OSTI)

Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.

Miller, Paul Albert

2010-11-01T23:59:59.000Z

266

Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies  

Broader source: Energy.gov [DOE]

This factsheet describes a project to develop direct steelmaking through the combination of microwave, electric arc, and exothermal heating, a process which is meant to eliminate traditional, intermediate steelmaking steps.

267

UPb and geochemical evidence for a Cryogenian magmatic arc in central Novaya Zemlya, Arctic Russia  

E-Print Network [OSTI]

U­Pb and geochemical evidence for a Cryogenian magmatic arc in central Novaya Zemlya, Arctic Russia-0349 Oslo, Norway Introduction The High Arctic of Scandinavia and Russia consists of a collage

Svensen, Henrik

268

E-Print Network 3.0 - arc welding robot Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

robot Search Powered by Explorit Topic List Advanced Search Sample search results for: arc welding robot Page: << < 1 2 3 4 5 > >> 1 ORIGINAL ARTICLE Development of a mobile...

269

E-Print Network 3.0 - ac electric arc Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Powered by Explorit Topic List Advanced Search Sample search results for: ac electric arc Page: << < 1 2 3 4 5 > >> 1 The response of the azimuthal component of the...

270

Microstructure and Properties of Nanostructured Calcium Phosphate/Titania Porous Coatings via Micro Arc Oxidation  

Science Journals Connector (OSTI)

Crystalline Calcium Phosphate-TiO2 nanostructured porous layers were fabricated via micro arc oxidation technique under different times to investigate how...2 inner layer during the MAO growth. Based on XRD patte...

Sakine Abbasi; Hamid Reza Rezaie…

2013-01-01T23:59:59.000Z

271

Improving the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs, and Side Vents  

Broader source: Energy.gov [DOE]

This factsheet describes the benefits of a high-performance aluminum bronze alloy to basic oxygen furnace and electric arc furnace components such as hoods, roofs, and side vents.

272

Quick surface treatment of AZ31B by AC micro-arc oxidation  

Science Journals Connector (OSTI)

In order to explore an effective way to shorten treatment time and enhance the quality of treatment coating, AC micro-arc oxidation was conducted to treat the surface of ... KF+KOH treatment solution. The influen...

Shenglin Wang ???; Peng Zhang ??; Yunhui Du…

2014-08-01T23:59:59.000Z

273

Kinetics and Properties of Micro Arc Oxidation Coatings Deposited on Commercial Al Alloys  

Science Journals Connector (OSTI)

The micro arc oxidation (MAO) technique is being increasingly recognized...6Si2O13 (mullite) is observed to form. With increasing Si content, the corresponding mullite phase also increases. Increasing mullite con...

L. Rama krishna; A. Sudha Purnima…

2007-02-01T23:59:59.000Z

274

Microstructure and corrosion resistance of ultrasonic micro-arc oxidation biocoatings on magnesium alloy  

Science Journals Connector (OSTI)

The ultrasonic micro-arc oxidation (UMAO) was used to fabricate ceramic ... showed that ultrasound improved the homogeneous distribution of micro-porous structure. The coatings were mainly composed...

Lijie Qu; Muqin Li; Miao Liu; Erlin Zhang; Chen Ma

2013-09-01T23:59:59.000Z

275

Simulation of hardened layer formation at micro-arc oxidation of aluminum specimens  

Science Journals Connector (OSTI)

In this paper, some model representations on a process of hardened surface layer formation are presented; they were developed on the basis of the analysis of physical processes that occur in the course of micro-arc

N. Yu. Dudareva

2008-09-01T23:59:59.000Z

276

A parameter design of CNC plasma-arc cutting of carbon steel plates using robust design  

Science Journals Connector (OSTI)

An optimisation of the cutting parameters during CNC plasma-arc cutting of St37 mild steel plates is attempted using robust design. The process parameters tested were plate thickness, cutting speed, arc ampere, arc voltage, air pressure, pierce height, and torch standoff distance. An orthogonal matrix experiment [L18 (21 × 37) ] was conducted and the right bevel angle was measured and optimised according to the process parameters using an analysis of means and an analysis of variances. The results show that the arc ampere has an effect mainly on the bevel angle (50.89%), while the plate thickness and torch standoff distance also have an influence of 6.22 and 15.9% respectively. The other parameters have an F factor smaller than one, and thus their variations do not significantly affect the bevel angle in the experimental region. Finally, an additive model was applied on the experimental results to predict the optimum combination and was compared with actual values.

John Kechagias; Michael Billis; Stergios Maropoulos

2010-01-01T23:59:59.000Z

277

Carbon nanostructures production by AC arc discharge plasma process at atmospheric pressure  

Science Journals Connector (OSTI)

Carbon nanostructures have received much attention for a wide range of applications. In this paper, we produced carbon nanostructures by decomposition of benzene using AC arc discharge plasma process at atmospheric pressure. Discharge was carried out ...

Shenqiang Zhao; Ruoyu Hong; Zhi Luo; Haifeng Lu; Biao Yan

2011-01-01T23:59:59.000Z

278

Explosive electron emission and the portion model of the electric arc  

Science Journals Connector (OSTI)

Some parameters and dependences characteristic of the electric arc phenomenon had no satisfactory explanation for a ... number of important ideas in the physics of electric discharges. At a meeting of the RAS Pre...

Gennadii Andreevich Mesyats

2014-07-01T23:59:59.000Z

279

Computation of electric-arc parameters taking account of convective and radiant losses  

Science Journals Connector (OSTI)

An approximate solution of the problem of an electrical arc in a turbulent argon stream is obtained, taking into account convective and radiant energy losses in the discharge channel at atmospheric pressure.

N. A. Zyrichev

1971-10-01T23:59:59.000Z

280

Obtaining Carbon Nanoparticles with the Use of Electric?Arc Discharge between Coaxial Electrodes  

Science Journals Connector (OSTI)

The structure of a setup and the results of experiments on obtaining carbon nanostructures with the use of a d.c. arc discharge between coaxial graphite electrodes have been presented. The discharge was stabil...

V. V. Chuprasov; M. S. Tret'yak…

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Investigation of condensed products of graphite evaporation in an electric arc in argon and helium atmosphere  

Science Journals Connector (OSTI)

The composition of products formed in the discharge chamber at the synthesis of nanostructures by arc discharge was investigated. The fullerene soot obtained in an argon atmosphere was shown to contain at leas...

V. I. Podgornyi; S. D. Kushch; A. N. Yakovlev…

2011-02-01T23:59:59.000Z

282

Ethanol and E85 Reforming Assisted by a Non-thermal Arc Discharge  

Science Journals Connector (OSTI)

Ethanol and E85 Reforming Assisted by a Non-thermal Arc Discharge ... The input electric power is expressed in terms of the percentage of Qfuel·LHVfuel, and is noted as %LHV. ... for electricity prodn. ...

Guillaume Petitpas; José Gonzalez-Aguilar; Adeline Darmon; Laurent Fulcheri

2010-03-25T23:59:59.000Z

283

Studies on erosion of silicone rubber exposed to partial arc discharges  

Science Journals Connector (OSTI)

The effect of electrolyte conductivity on the partial arc discharge development between two electrolyte electrodes on a silicone rubber sheet surface was investigated. Tests were executed by placing the salt-waterlogged glass-filter paper on a silicone rubber sheet to simulate a polluted electrolyte layer, and partial arc discharges with a constant current value of 10 mA were observed. It was found that the formation of an arc channel and a temperature distribution on the sample surface varied with the electrolyte conductivity. In addition, the relation between the electrolyte conductivity and the weight loss due to the heat erosion of specimens was also investigated by a 3D morphological observation and a simulated calculation. The partial arc discharge did significantly not influence on the sample surface erosion under serious polluted conditions. In contrast, the severest erosion appeared under the light pollution with comparatively lower conductivity of the electrolyte electrodes.

Kenichi Haji; Yong Zhu; Masahisa Otsubo; Tatsuya Sakoda

2008-01-01T23:59:59.000Z

284

Fullerene Formation in Carbon Arc:? Electrode Gap Dependence and Plasma Spectroscopy  

Science Journals Connector (OSTI)

The arc discharge technique is presently considered the most efficient method for the production of fullerene. ... The experiments were carried out in a fullerene arc reactor operating in a semi-continuous fashion, described previously in detail by Huczko et al.20 On the basis of earlier work,20-22 the parameters, ac or dc feeding mode, input power, buffer gas, and pressure, were optimized and electrode gaps between 0.5 and 4 mm were used for dc arcing. ... The interelectrode gap strongly influences the electric properties of the arc and characteristics of generated carbon plasma as well as the radiation level and heat exchange between the plasma and the surrounding high-temperature zone. ...

Andrzej Huczko; Hubert Lange; Przemyslaw Byszewski; Magdalena Poplawska; Andrzej Starski

1997-02-13T23:59:59.000Z

285

The stability and the conditions for initiation of electric-arc discharges in railguns  

Science Journals Connector (OSTI)

Characteristic physical features of plasma formations in high-velocity sliding electric contacts are treated, in particular, those in railguns with both electric-arc and metal armatures. Comparison is made of ...

A. P. Glinov

2007-04-01T23:59:59.000Z

286

Application of electrostatic Langmuir probe to atmospheric arc plasmas producing nanostructures  

SciTech Connect (OSTI)

The temporal evolution of a high pressure He arc producing nanotubes was considered and the Langmuir probe technique was applied for plasma parameter measurements. Two modes of arc were observed: cathodic arc where discharge is supported by erosion of cathode material and anodic arc which is supported by ablation of the anode packed with carbon and metallic catalysts in which carbon nanotubes are synthesized. Voltage-current (V-I) characteristics of single probes were measured and unusually low ratio of saturation current on positively biased probe to that on negatively biased of about 1-4 was observed. This effect was explained by increase of measured current at the negatively biased probe above the level of ion saturation current due to secondary electron emission from the probe surface. Since utilization of standard collisionless approach to determine plasma parameters from the measured V-I characteristic is not correct, the electron saturation current was used to estimate the plasma density.

Shashurin, A.; Li, J.; Zhuang, T.; Keidar, M. [Department of Mechanical and Aerospace Engineering, School of Engineering and Applied Science, George Washington University, Washington, District of Columbia 20052 (United States); Beilis, I. I. [School of Electrical Engineering, Tel Aviv University, Ramat Aviv 69978 (Israel)

2011-07-15T23:59:59.000Z

287

Numerical Investigation of the Effect of the Cathode Geometry on the Characteristics of an Electric Arc  

Science Journals Connector (OSTI)

The effect of the cathode geometry on the characteristics of an electric arc is treated. It is found that the characteristics of plasma in discharges with cathodes of different geometry (cone, ... . It is assumed...

R. M. Urusov; T. E. Urusova

288

A cascaded photonic crystal fiber Mach–Zehnder interferometer formed by extra electric arc discharges  

Science Journals Connector (OSTI)

In this paper, a cascaded Mach–Zehnder interferometer based on a photonic crystal fiber is reported. It is demonstrated that by applying a small dose of extra arc discharge to the photonic crystal fiber sensin...

Y. Geng; X. Li; X. Tan; Y. Deng; Y. Yu

2011-03-01T23:59:59.000Z

289

Two-dimensional kinetic model of short high-current vacuum-arc discharge  

Science Journals Connector (OSTI)

A two-dimensional mathematical model of a short high-current vacuum-arc discharge is developed, according to which magnetized electrons ... a free flight regime in a two-dimensional electric field. The proposed m...

Ya. I. Londer; K. N. Ul’yanov

2010-03-01T23:59:59.000Z

290

The current-voltage characteristic of a hot-cathode electric arc at low pressures  

Science Journals Connector (OSTI)

It has been shown that in a hot-cathode electric arc operating at low pressures of the working ... drop arises that results in an increase in discharge voltage with current even before the transition of the discharge

C. P. Nikulin

2011-03-01T23:59:59.000Z

291

Super-conducting niobium films produced by means of UHV arc  

Science Journals Connector (OSTI)

The paper shows that high-quality super-conducting Nb films can be deposited by means of arc discharges under ultra-high vacuum conditions. The critical temperatureT c...of Nb-films obtained with ...

J. Langner; M. J. Sadowski; K. Czaus; R. Mirowski…

2004-03-01T23:59:59.000Z

292

E-Print Network 3.0 - arc energy limiting Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

energy limiting Page: << < 1 2 3 4 5 > >> 1 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 50, NO. 3, JUNE 2001 697 Robust Sensing of Arc Length Summary: the...

293

Controlling electrode gap during vacuum arc remelting at low melting current  

DOE Patents [OSTI]

An apparatus and method are disclosed for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived. 5 figs.

Williamson, R.L.; Zanner, F.J.; Grose, S.M.

1997-04-15T23:59:59.000Z

294

E-Print Network 3.0 - assisted plasma arc Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Groupe d'Optique Atomique Collection: Physics 8 Gliding arc in tornado using a reverse vortex flow Chiranjeev S. Kalra, Young I. Cho,a Summary: . Instead the ignition was plasma...

295

E-Print Network 3.0 - arc discharge effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

de mathmatiques Collection: Mathematics 5 Gliding arc in tornado using a reverse vortex flow Chiranjeev S. Kalra, Young I. Cho,a Summary: nonequilib- rium plasma is to use...

296

E-Print Network 3.0 - arc discharge ion Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Texas at Austin Collection: Engineering 8 Gliding arc in tornado using a reverse vortex flow Chiranjeev S. Kalra, Young I. Cho,a Summary: nonequilib- rium plasma is to use...

297

Comparative Study on the Electronic Structure of Arc-Discharge and Catalytic Carbon Nanotubes  

Science Journals Connector (OSTI)

Comparative Study on the Electronic Structure of Arc-Discharge and Catalytic Carbon Nanotubes ... A perfect nanotube may be thought of as a cylindrical graphene sheet composed only of hexagons with a few pentagonal rings needed to close the tips.1 The typical carbon nanotubes formed under high temperature conditions, which can be induced by an electric arc for example, are predominantly straight having the largest numbers of topological defects at their ends. ...

L. G. Bulusheva; A. V. Okotrub; I. P. Asanov; A. Fonseca; J. B. Nagy

2001-05-05T23:59:59.000Z

298

Three Stages Modeling of n-Octane Reforming Assisted by a Nonthermal Arc Discharge  

Science Journals Connector (OSTI)

Three Stages Modeling of n-Octane Reforming Assisted by a Nonthermal Arc Discharge ... After a description of the model and its main assumptions, a parametric analysis of plasma reformer performance addressing the influence of plasma volume, H2O/C ratio, O/C ratio, and input electric power is presented. ... Most of them were particularly dealt with technologies based on arc discharges. ...

José Gonzalez-Aguilar; Guillaume Petitpas; Alexandre Lebouvier; Jean-Damien Rollier; Adeline Darmon; Laurent Fulcheri

2009-09-08T23:59:59.000Z

299

A study of the precursor effect in an arc-driven shock tube  

E-Print Network [OSTI]

the electrical arc discharge voltage used. Here the predominant precursor source has been found to be photoionization. These studies generally used micro- wave diagnostic equipment. Theoretical results so far have been divided between photoionization... the electrical arc discharge voltage used. Here the predominant precursor source has been found to be photoionization. These studies generally used micro- wave diagnostic equipment. Theoretical results so far have been divided between photoionization...

Reed, James Alan

2012-06-07T23:59:59.000Z

300

Vacuum arc ignition by penning discharge in a strong magnetic field  

SciTech Connect (OSTI)

Vacuum arc with cathode spots on the cold electrode is widely used as a plasma generator in a such kind of devices like metal ion sources, plasma cathode electron guns, thing films deposition facilities and others. Most vacuum arc devices utilize a high voltage discharge across an insulator surface to provide a trigger plasma which in turn initiates the main arc discharge. Operation of vacuum arc in a repetitively pulsed mode required a stable triggering system for the long time. But with a discharge across the insulators the number of stable pulses is limited by 100,000 or little bit more. The better method for vacuum arc ignition is low pressure discharge. As shown in this paper it is possible to increase the lifetime of the ignition system in 10 times at least, but negative characteristic of this system is a relatively high pressure (about 0.1 mtorr). In some kinds of vacuum arc applications it is impermissible because it leads to the {open_quotes}contamination{close_quotes} of the metal plasma by the gaseous one. In order to decrease the background pressure, using the gas discharge ignition system for vacuum arc, Penning discharge is suggested. The main new feature of this system is an applying the strong magnetic field not only for stabilization of the cathode spot moving and for the rise the high charge states of ions in metal plasma, but also for the essential decrease the lowest point of the background gas pressure when the Penning discharge is still in a stable operation. Under the stable mode of Penning discharge there was always a stable vacuum arc ignition.

Nikolaev, A.G.; Schanin, P.M.; Yushkov, G.Yu. [High Current Electronics Inst., Tomsk (Russian Federation)] [and others

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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301

Temperature dependence of the gaps of high-temperature superconductors in the Fermi-arc region  

Science Journals Connector (OSTI)

It is shown how in a high-temperature superconductor, the length of the Fermi arc can be obtained from the doping dependence of the pseudogap and the superconducting gap. In the momentum region spanned by the Fermi arc, the pseudogap temperature dependence follows that of the superconducting gap. The close interconnection of the two gaps suggests that they are both an essential part of the high-temperature superconductivity.

S. Hüfner and F. Müller

2008-07-23T23:59:59.000Z

302

Zeeman Effects in the Arc Spectrum of Ruthenium  

Science Journals Connector (OSTI)

Measurements on resolved Zeeman patterns of 450 lines of normal ruthenium are reported. Five exposures to each polarized component of the light from a 4-ampere arc, operated in magnetic fields of intensity between 71,000 and 92,200 gauss, resulted in 85 plates which were measured on an automatic comparator. J and g values have been determined from the various patterns. When data from the various lines arising from a given term are averaged, g values for 140 terms are obtained which appear to be correct to within ±0.003 unit. The results obtained have been used to further the classification of Ru I, and to aid in the assignment of L and S values to highly perturbed terms. Though g values frequently depart strongly from values calculated for LS coupling, it is usually possible to assign meaningful L and S designations. Asymmetrical patterns in lines arising from the terms y5D30 and y5D40 are discussed.

George R. Harrison and J. Rand McNally; Jr.

1940-10-15T23:59:59.000Z

303

Stainless steel submerged arc weld fusion line toughness  

SciTech Connect (OSTI)

This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.

Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

1995-04-01T23:59:59.000Z

304

GALAXY HALO TRUNCATION AND GIANT ARC SURFACE BRIGHTNESS RECONSTRUCTION IN THE CLUSTER MACSJ1206.2-0847  

SciTech Connect (OSTI)

In this work, we analyze the mass distribution of MACSJ1206.2-0847, particularly focusing on the halo properties of its cluster members. The cluster appears relaxed in its X-ray emission, but has a significant amount of intracluster light that is not centrally concentrated, suggesting that galaxy-scale interactions are still ongoing despite the overall relaxed state. The cluster lenses 12 background galaxies into multiple images and one galaxy at z = 1.033 into a giant arc and its counterimage. The multiple image positions and the surface brightness (SFB) distribution of the arc, which is bent around several cluster members, are sensitive to the cluster galaxy halo properties. We model the cluster mass distribution with a Navarro-Frenk-White profile and the galaxy halos with two parameters for the mass normalization and the extent of a reference halo assuming scalings with their observed near-infrared light. We match the multiple image positions at an rms level of 0.''85 and can reconstruct the SFB distribution of the arc in several filters to a remarkable accuracy based on this cluster model. The length scale where the enclosed galaxy halo mass is best constrained is about 5 effective radii-a scale in between those accessible to dynamical and field strong-lensing mass estimates on the one hand and galaxy-galaxy weak-lensing results on the other hand. The velocity dispersion and halo size of a galaxy with m{sub 160W,AB} = 19.2 and M{sub B,Vega} = -20.7 are {sigma} = 150 km s{sup -1} and r Almost-Equal-To 26 {+-} 6 kpc, respectively, indicating that the halos of the cluster galaxies are tidally stripped. We also reconstruct the unlensed source, which is smaller by a factor of {approx}5.8 in area, demonstrating the increase in morphological information due to lensing. We conclude that this galaxy likely has star-forming spiral arms with a red (older) central component.

Eichner, Thomas; Seitz, Stella; Monna, Anna [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Suyu, Sherry H. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Halkola, Aleksi [Institute of Medical Engineering, University of Luebeck, Ratzeburger Allee 160 23562 Luebeck (Germany); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, Adi [Institut fuer Theoretische Astrophysik, ZAH, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Coe, Dan; Postman, Marc; Koekemoer, Anton; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Rosati, Piero [ESO-European Southern Observatory, D-85748 Garching bei Muenchen (Germany); Grillo, Claudio; Host, Ole [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Balestra, Italo [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Zheng, Wei; Lemze, Doron [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Broadhurst, Tom [Department of Theoretical Physics, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); Moustakas, Leonidas [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, Pasadena, CA 91109 (United States); Molino, Alberto [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada E-18008 (Spain); and others

2013-09-10T23:59:59.000Z

305

Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.  

SciTech Connect (OSTI)

Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

2012-01-01T23:59:59.000Z

306

JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs  

SciTech Connect (OSTI)

We propose a demonstration experiment for a new concept of a 'dogbone' RLA with multi-pass return arcs -- JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we describe a test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected in the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The hardware requirements are not very demanding making it straightforward to implement. Such an RLA may have applications going beyond muon acceleration: in medical isotope production, radiation cancer therapy and homeland security.

Bogacz, Slawomir Alex; Krafft, Geoffrey A.; Morozov, Vasiliy S.; Roblin, Yves R.

2013-06-01T23:59:59.000Z

307

Temporal Development of Ion Beam Mean Charge State in PulsedVacuum Arc Ion Sources  

SciTech Connect (OSTI)

Vacuum arc ion sources, commonly also known as "Mevva" ionsources, are used to generate intense pulsed metal ion beams. It is knownthat the mean charge state of the ion beam lies between 1 and 4,depending on cathode material, arc current, arc pulse duration, presenceor absence of magnetic field at the cathode, as well background gaspressure. A characteristic of the vacuum arc ion beam is a significantdecrease in ion charge state throughout the pulse. This decrease can beobserved up to a few milliseconds, until a "noisy" steady-state value isestablished. Since the extraction voltage is constant, a decrease in theion charge state has a proportional impact on the average ion beamenergy. This paper presents results of detailed investigations of theinfluence of arc parameters on the temporal development of the ion beammean charge state for a wide range of cathode materials. It is shown thatfor fixed pulse duration, the charge state decrease can be reduced bylower arc current, higher pulse repetition rate, and reduction of thedistance between cathode and extraction region. The latter effect may beassociated with charge exchange processes in the dischargeplasma.

Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

2007-06-21T23:59:59.000Z

308

The Reactivity and Structural Dynamics of Supported Metal Nanoclusters Using Electron Microscopy, in situ X-Ray Spectroscopy, Electronic Structure Theories, and Molecular Dynamics Simulations.  

SciTech Connect (OSTI)

The distinguishing feature of our collaborative program of study is the focus it brings to emergent phenomena originating from the unique structural/electronic environments found in nanoscale materials. We exploit and develop frontier methods of atomic-scale materials characterization based on electron microscopy (Yang) and synchrotron X-ray absorption spectroscopy (Frenkel) that are in turn coupled innately with advanced first principles theory and methods of computational modeling (Johnson). In the past year we have made significant experimental advances that have led to important new understandings of the structural dynamics of what are unquestionably the most important classes of heterogeneous catalysts—the materials used to both produce and mitigate the consequences of the use of liquid hydrocarbon fuels.

Judith C. Yang; Ralph G. Nuzzo, Duane Johnson, Anatoly Frenkel

2008-07-01T23:59:59.000Z

309

Application of Centrifugation to the Large-Scale Purification of Electric Arc-Produced Single-Walled Carbon Nanotubes  

Science Journals Connector (OSTI)

Application of Centrifugation to the Large-Scale Purification of Electric Arc-Produced Single-Walled Carbon Nanotubes ... Electric arc-discharge AP-SWNTs were obtained from Carbon Solutions, Inc. (www.carbonsolution.com). ... Using microwave processing and 4 M HCl acid reflux for 6 h we were able to remove residual metal (Ni, Y) in arc-discharge SWNTs to a level lower than 0.2 wt % (?0.04 at. ...

Aiping Yu; Elena Bekyarova; Mikhail E. Itkis; Danylo Fakhrutdinov; Robert Webster; Robert C. Haddon

2006-07-08T23:59:59.000Z

310

Jurassic arc volcanism on Crimea (Ukraine): Implications for the paleo-subduction zone configuration of the Black Sea region  

E-Print Network [OSTI]

Jurassic arc volcanism on Crimea (Ukraine): Implications for the paleo-subduction zone margin. Crimea (Ukraine), a peninsula in the northern Black Sea, represents the northernmost region

Utrecht, Universiteit

311

Axial Distributions of Spectral Line Intensities in the Arc Under the Influence of External Rotating Magnetic Field  

Science Journals Connector (OSTI)

The influence of external rotating magnetic field (RMF) on the electric arc plasma, and therefore the axial distributions of the spectral line intensities and the atomic...

Pavlovic, B V; Mihailidi, T A

1981-01-01T23:59:59.000Z

312

Electron Model Of A Dogbone RLA With Multi-Pass Arcs  

SciTech Connect (OSTI)

The design of a dogbone Recirculated Linear Accelerator, RLA, with linear-field multi-pass arcs was earlier developed [1] for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected at the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to the frequency readily available at CEBAF: 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it straightforward to implement

Beard, Kevin B. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States) and MUONS Inc., Batavia, IL (United States); Roblin, Yves R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Bogacz, Slawomir Alex [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Krafft, Geoffrey A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2012-09-01T23:59:59.000Z

313

Investigation on oblique shock wave control by arc discharge plasma in supersonic airflow  

SciTech Connect (OSTI)

Wedge oblique shock wave control by arc discharge plasma in supersonic airflow was investigated theoretically, experimentally, and numerically in this paper. Using thermal choking model, the change in oblique shock wave was deduced, which refer that the start point of shock wave shifts upstream, the shock wave angle decreases, and its intensity weakens. Then the theoretical results were validated experimentally in a Mach 2.2 wind tunnel. On the test conditions of arc discharge power of approx1 kW and arc plasma temperature of approx3000 K, schlieren photography and gas pressure measurements indicated that the start point of shock wave shifted upstream of approx4 mm, the shock wave angle decreased 8.6%, and its intensity weakened 8.8%. The deduced theoretical results match the test results qualitatively, so thermal mechanism and thermal choking model are rational to explain the problem of oblique shock wave control by arc discharge plasma. Finally, numerical simulation was developed. Based on thermal mechanism, the arc discharge plasma was simplified as a thermal source term that added to the Navier-Stokes equations. The simulation results of the change in oblique shock wave were consistent with the test results, so the thermal mechanism indeed dominates the oblique shock wave control process.

Wang Jian; Li Yinghong [Engineering College, Air Force Engineering University, Xi'an 710038 (China); Xing Fei [College of Economics and Management, Northwest University of Politics and Law, Xi'an 710063 (China)

2009-10-01T23:59:59.000Z

314

A study of vacuum arc ion velocities using a linear set of probes  

SciTech Connect (OSTI)

The most likely velocity of ions moving away from vacuum arc cathode spots was measured using a set of probes along the path of plasma expansion. The goal was to determine how much, if any, change of the ion drift velocity occurs in the expanded plasma. The arc discharge current was perturbed to create plasma density markers whose travel is picked up by the set of probes. It was found that the perturbation with current oscillations did not result in consistent data because ion current maxima and minima are not only determined by the plasma production but by the transients of the arc pulse and by the asymmetry of the ion velocity distribution function. Perturbation with a short current spike was more conclusive. The ion velocity was measured to be slightly reduced with increasing distance from the cathode, which can be explained by collisions of ions with the background of neutrals. The ion velocity was increased when the arc current was increased, which correlated with enhanced arc voltage and power dissipation. The ion velocity could be enhanced when the plasma was produced in a non-uniform magnetic field.

Hohenbild, Stefan; Grubel, Christoph; Yushkov, Georgy Yu.; Oks, Efim M.; Anders, Andre

2008-07-15T23:59:59.000Z

315

Application of cathodic arc deposited amorphous hard carbon films to the head/disk tribology  

SciTech Connect (OSTI)

Amorphous hard carbon films deposited by filtered cathodic arc deposition exhibit very high hardness and elastic modulus, high mass density, low coefficient of friction, and the films are very smooth. All these properties are beneficial to applications of these films for the head/disk interface tribology. The properties of cathodic arc deposited amorphous carbon films are summarized, and they are compared to sputter deposited, hydrogenated (CH{sub x}), and nitrogenated (CN{sub x}) carbon films which are the present choice for hard disk and slider coatings. New developments in cathodic arc coaters are discussed which are of interest to the disk drive industry. Experiments on the nanotribology, mass density and hardness, corrosion behavior, and tribochemical behavior of cathodic arc films are reported. A number of applications of cathodic arc deposited films to hard disk and slider coatings are described. It is shown that their tribological performance is considerably better compared to CH{sub x} and CN{sub x} films.

Anders, S. [Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.; Bhatia, C.S. [SSD/IBM, San Jose, CA (United States); Fong, W.; Lo, R.Y.; Bogy, D.B. [Univ. of California, Berkeley, CA (United States). Computer Mechanics Lab.

1998-04-01T23:59:59.000Z

316

Arcing fault identification using combined Gabor Transform-neural network for transmission lines  

Science Journals Connector (OSTI)

Abstract This paper presents an intelligent identification scheme for transient faults in transmission systems using Gabor Transform (GT) and Artificial Neural Network (ANN). The successful discrimination between arcing and permanent faults can be then utilized for realize a reliable operation of autoreclosure systems. The proposed algorithm employs the GT as a signal processing technique and the ANN for pattern recognition and classification processes. The use of GT is motivated by the fact that the Gabor elementary functions have distinctive an optimal localization property in the joint time and frequency domains, which leads to an optimal feature extraction. The extracted GT coefficients are used as the inputs to a three layer feedforward ANN. The generalization capabilities of neural networks together with the GT are expected to discriminate between arcing and permanent fault cases successfully. The fault behavior is simulated by ATP/EMTP where the arc model is realized using universal arc representation. Finally, the possibility of hardware implementation of the proposed scheme is visualized in order to verify its practicality and suitability for real field operation. The results show that combining of GT along with \\{ANNs\\} achieves an excellent performance to discriminate between arcing and permanent faults with eliminating the impacts of fault resistance, fault location and fault inception angle as compared with conventional discriminators.

Tamer A. Kawady; Nagy I. Elkalashy; Ayman E. Ibrahim; Abdel-Maksoud I. Taalab

2014-01-01T23:59:59.000Z

317

Linear Fixed-Field Multi-Pass Arcs for Recirculating Linear Accelerators  

SciTech Connect (OSTI)

Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.

V.S. Morozov, S.A. Bogacz, Y.R. Roblin, K.B. Beard

2012-06-01T23:59:59.000Z

318

Optimal control strategies for load carrying drones Alicia Arce  

E-Print Network [OSTI]

is an interesting and challenging issue to deal with. Throughout this paper, a dynamic model based on first by two drones. Afterwards, different control techniques are implemented and compared by simulations. The invention of light materials, low energy consumption machines and high performance processing units led

Boyer, Edmond

319

A Catalyst Wire-feed Arc Discharge for Synthesis of Carbon Nanotubes and  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

A Catalyst Wire-feed Arc Discharge for Synthesis of Carbon Nanotubes and A Catalyst Wire-feed Arc Discharge for Synthesis of Carbon Nanotubes and Graphene Particles This invention pertains to a highly effective arc-based synthesis of single wall carbon nanotubes and graphene particles using catalysts in the form of wires made from ion group alloys instead of commonly used catalyst powders. The catalyst wire can be introduced into the discharge either from the anode or cathode regions or into the inter-electrode gap. The catalyst introduction can be done automatically and controlled using feedback based on the ablation of the graphite electrode. To maintain simplicity and attractiveness for industrial applications, it is desirable that the catalyst composition be contained in a single wire alloy. No.: M-808 Inventor(s): Yevgeny Raitses

320

Roughening and removal of surface contamination from beryllium using negative transferred-arc cleaning  

SciTech Connect (OSTI)

Negative transferred-arc (TA) cleaning has been used extensively in the aerospace industry to clean and prepare surfaces prior to plasma spraying of thermal barrier coatings. This non-line of sight process can improve the bond strength of plasma sprayed coatings to the substrate material by cleaning and macroscopically roughening the surface. A variation of this cleaning methodology is also used in gas tungsten arc (GTA) welding to cathodically clean the surfaces of aluminum and magnesium prior to welding. Investigations are currently being performed to quantify the degree in which the negative transferred-arc process can clean and roughen metal surfaces. Preliminary information will be reported on the influence of processing conditions on roughening and the removal of carbon and other contaminates from the surface of beryllium. Optical, spectral and electrical methods to quantify cleaning of the surface will also be discussed. Applications for this technology include chemical-free precision cleaning of beryllium components.

Castro, R.G.; Hollis, K.J.; Elliott, K.E. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

1997-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Cylindrical bubble evolution and acoustic signature through the arc phase of an electrical discharge.  

Science Journals Connector (OSTI)

The arc phase of an electrical discharge in salt water is investigated using a 1?D nonlinear fluid model in cylindrical (r) coordinates. For most electrode geometries the arc phase is more accurately modeled using a cylindrical geometry compared to the usual and simpler to implement spherical model. This is due to the fact that until the bubble radius is comparable to the distance between electrodes the preferred geometry is cylindrical. Both the bubbles external (water) and internal (dissociated water and plasma) are discretized and modeled with nonlinear fluid equations. The model includes the energy flow from the capacitor into the plasma arc through its resistivity and then finally into the hydroacoustic pulse. Simulation results will be compared to experiments. Also the efficiency of various electrode configurations will be investigated. [Work supported by the Office of Naval Research.

David L. Fisher; Robert L. Rogers

1996-01-01T23:59:59.000Z

322

Simulations of the magnet misalignments, field errors and orbit correction for the SLC north arc  

SciTech Connect (OSTI)

Given the intensity of linac bunches and their repetition rate the desired luminosity of SLC 1.0 x 10/sup 30/ cm/sup -2/ sec/sup -1/ requires focusing the interaction bunches to a spot size in the micrometer (..mu..m) range. The lattice that achieves this goal is obtained by careful design of both the arcs and the final focus systems. For the micrometer range of the beam spot size both the second order geometric and chromatic aberrations may be completely destructive. The concept of second order achromat proved to be extremely important in this respect and the arcs are built essentially as a sequence of such achromats. Between the end of the linac and the interaction point (IP) there are three special sections in addition to the regular structure: matching section (MS) designed for matching the phase space from the linac to the arcs, reverse bend section (RB) which provides the matching when the sign of the curvature is reversed in the arc and the final focus system (FFS). The second order calculations are done by the program TURTLE. Using the TURTLE histogram in the x-y plane and assuming identical histogram for the south arc, corresponding 'luminosity' L is found. The simulation of the misalignments and error effects have to be done simultaneously with the design and simulation of the orbit correction scheme. Even after the orbit is corrected and the beam can be transmitted through the vacuum chamber, the focusing of the beam to the desired size at the IP remains a serious potential problem. It is found, as will be elaborated later, that even for the best achieved orbit correction, additional corrections of the dispersion function and possibly transfer matrix are needed. This report describes a few of the presently conceived correction schemes and summarizes some results of computer simulations done for the SLC north arc. 8 references, 12 figures, 6 tables.

Kheifets, S.; Chao, A.; Jaeger, J.; Shoaee, H.

1983-11-01T23:59:59.000Z

323

Increasing the length of single-wall carbon nanotubes in a magnetically enhanced arc discharge  

SciTech Connect (OSTI)

It is demonstrated that a magnetic field has a profound effect on the length of a single-wall carbon nanotube (SWCNT) synthesized in the arc discharge. The average length of SWCNT increases by a factor of 2 in discharge with magnetic field as compared with the discharge without magnetic field, and the yield of long nanotubes with lengths above 5 {mu}m also increases. A model of SWCNT growth on metal catalyst in arc plasma was developed. Monte-Carlo simulations confirm that the increase of the plasma density in the magnetic field leads to an increase in the nanotube growth rate and thus leads to longer nanotubes.

Keidar, Michael [Department of Mechanical and Aerospace Engineering, George Washington University, Washington, District of Columbia 20052 (United States); Levchenko, Igor; Ostrikov, Kostya [Plasma Nanoscience, School of Physics, The University of Sydney, Sydney, New South Wales 2006 (Australia); Arbel, Tamir [Department of Material Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Alexander, Myriam [Department of Geophysical Science, University of Chicago, Chicago, Illinois 60637 (United States); Waas, Anthony M. [Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2008-01-28T23:59:59.000Z

324

Emission and Absorption Spectroscopy of Carbon Arc Plasma during Formation of Carbon Magnetic Encapsulates  

SciTech Connect (OSTI)

Plasma diagnostics of carbon arc discharge under conditions of carbon magnetic encapsulates formation was performed by emission and absorption spectroscopy. Content of C{sub 2} and Fe species, rotational temperatures of excited (d {sup 3} product {sub g}) and non-excited (a {sup 3} product {sub u}) states, and excitation temperatures of a {sup 5}F and a {sup 3}F levels relatively to the a {sup 5}D level of Fe atoms were determined. The results pointed to a non-equilibrium state of carbon arc plasma under prevailing discharge conditions.

Lange, H.; Labedz, O.; Huczko, A.; Bystrzejewski, M. [Faculty of Chemistry, Warsaw University, Pasteur str. 1,02-093 Warsaw (Poland)

2011-11-29T23:59:59.000Z

325

Radial Mass Fraction Distributions In Ar+N Plasmas Produced In A Wall-Stabilized Arc  

SciTech Connect (OSTI)

Radial distributions of Ar mass fractions in plasmas produced in a wall-stabilized arc have been studied. Measurements have been performed for seven different mixtures of Ar+N2. The obtained results show that the radial distributions of Ar mass fractions strongly depend on the chemical composition of the plasma. In plasmas containing large amount of Ar the distributions have local minima at the arc axis (in high temperature plasma regions), whereas in plasmas consisting mainly of nitrogen the distributions reveal maxima on the discharge axis.

KsiaPzek, Ireneusz [Institute of Physics, Opole University, ul. Oleska 48, 45-052 Opole (Poland)

2006-01-15T23:59:59.000Z

326

Gnrateur Plasma d'Arc Air de 2 kW ABDERRAHMANE HALIS1  

E-Print Network [OSTI]

1 Générateur à Plasma d'Arc à Air de 2 kW ABDERRAHMANE HALIS1 , BERNARD PATEYRON2 , MOHAMMED EL : Une torche plasma d'arc à air de moins de 2 kW a été conçue et réalisée dans le laboratoire de imposent l'usage d'une flamme plasma : soudage, découpage, rechargement de métaux, traitement thermique de

Boyer, Edmond

327

Preparation of Al2O3/TiO2-containing Coating on Aluminium Alloys by Micro-arc Oxidation  

Science Journals Connector (OSTI)

TiO2-containing ceramic coatings were deposited on the surface of aluminium alloys by micro-arc oxidition. Surface and cross-section topograph of ceramic coating were observed using scanning electron microscopy (SEM). The phase composition of ceramic ... Keywords: Micro-arc oxidation, TiO2 additive, Al2O3/TiO2 phase, antiwear behavior

Cheng Gao; Jinyong Xu; Yusheng Lan; Yonghui Ma; Weixiang Su; Yajuan Liu

2010-03-01T23:59:59.000Z

328

Instability of a Vacuum Arc Centrifuge M. J. Hole, R. S. Dallaqua, S. W. Simpson* and E. Del Bosco.  

E-Print Network [OSTI]

vapour ablated from the cathode of the discharge by the action of vacuum arcs (see Figure 1) with a metalInstability of a Vacuum Arc Centrifuge M. J. Hole, R. S. Dallaqua, S. W. Simpson* and E. Del Bosco of Electrical and Information Engineering, University of Sydney, N.S.W. 2006 Australia Laboratório Associado de

329

Impact of ArcA loss in Shewanella oneidensis revealed by comparative proteomics under aerobic and anaerobic conditions  

SciTech Connect (OSTI)

Shewanella inhabit a wide variety of niches in nature and can utilize a broad spectrum of electron acceptors under anaerobic conditions. How they modulate their gene expression to adapt is poorly understood. ArcA, homologue of a global regulator controlling hundreds of genes involved in aerobic and anaerobic respiration in E. coli, was shown to be important in aerobiosis/anaerobiosis of S. oneidensis as well. Loss of ArcA, in addition to altering transcription of many genes, resulted in impaired growth under aerobic condition, which was not observed in E. coli. To further characterize the impact of ArcA loss on gene expression on the level of proteome under aerobic and anaerobic conditions, liquid-chromatography-mass-spectrometry (LC-MS) based proteomic approach was employed. Results show that ArcA loss led to globally altered gene expression, generally consistent with that observed with transcripts. Comparison of transcriptomic and proteomic data permitted identification of 17 high-confidence ArcA targets. Moreover, our data indicate that ArcA is required for regulation of cytochrome c proteins, and the menaquinone level may play a role in regulating ArcA as in E. coli. Proteomic-data-guided growth assay revealed that the aerobic growth defect of ArcA mutant is presumably due to impaired peptide utilization.

Yuan, Jie; Wei, Buyun; Lipton, Mary S.; Gao, Haichun

2012-06-01T23:59:59.000Z

330

Presented in Conway, Lee, Merrimack and Plymouth, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Spring 2013  

E-Print Network [OSTI]

Topics covered: ArcGIS 10.1 Exploring GIS maps Basic GIS techniques $99 Workshop summary: Learn GIS maps.1 GIS techniques GIS data maintenance $495 standard, $349 reduced Workshop summary: Learn the ins and applications, participants learn how to use ArcGIS 10.1 to produce effective maps, edit and create GIS data

New Hampshire, University of

331

Presented in Lee and Concord, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Winter 2013  

E-Print Network [OSTI]

, 9am to 4pm January 17, 2013 Lee, NH Topics covered: ArcGIS 10.1 Exploring GIS maps Basic GIS: ArcGIS 10 Creating GIS maps.1 GIS techniques GIS data maintenance $495 standard, $349 reduced Skill.1 to produce effective maps, edit and create GIS data, as well as, conduct geospatial analysis. Participants

New Hampshire, University of

332

Characteristics of arcs between porous carbon electrodes E. CARVOU, J.L. Le GARREC, J. B.A. MITCHELL  

E-Print Network [OSTI]

develops into a full blown arc. The very high temperature in the arc (>6000°C) and the subsequent violent Transactions on Plasma Science, 99 (2013) 1-8" DOI : 10.1109/TPS.2013.2283581 #12;2 cable faults in order

Paris-Sud XI, Université de

333

Direct preparation of CaTi4 (PO4)6 coatings on the surface of titanium substrate by micro arc oxidation  

Science Journals Connector (OSTI)

CaTi4 (PO4)6...coatings was prepared on the surface of CP (commercially pure) Titanium substrate via micro arc oxidation in a newly designed electrolyte system. The preparation method –micro arc oxidation, as wel...

Zhongwei Zhao; Shimei Wen

2007-12-01T23:59:59.000Z

334

The Adhesion AND Growth of Both the Human Primary Gingival Epithelial Cells and Streptococcus Mutans on Micro-Arc Oxidized Titanium  

Science Journals Connector (OSTI)

With good osseointegration properties, micro-arc oxidation has now gradually become the key point ... but interface between the implant surface treated by micro-arc oxidation and gingival soft tissues has been se...

Jiangning Lv; Hongwei Li; Ying Mu; ShuMin Wang…

2014-11-01T23:59:59.000Z

335

Hall current layer formation in arc discharge across magnetic field and transfer of fast ions out of discharge  

SciTech Connect (OSTI)

In the work presented here the geometry of the Hall current layer in a plasma of the vacuum arc discharge in the transverse magnetic field are analyzed. The extraction of an intense pure flux of fast ions generated in the cathode spots with the help of the Hall layer is discussed. Experiments on the arc source of carbon fast ions are described. The anode geometry adequate to the mechanism of the arc current passage through the transverse magnetic field is found out experimentally. Up to 70% of fast ions are extracted out of the arc discharge in the arched magnetic field. In experiments, the Hall current layer formation in the vacuum arc discharge across magnetic field is confidently confirmed.

Bender, E.D.; Dimov, G.I.; Krivenko, A.S.; Razorenov, V.V. [Lumiks PTI Ltd., Yarne 81223 (Israel); Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

2006-01-15T23:59:59.000Z

336

How do I display the Map of Wind Farms csv coordinates in ArcMap software?  

Open Energy Info (EERE)

display the Map of Wind Farms csv coordinates in ArcMap software? display the Map of Wind Farms csv coordinates in ArcMap software? Home > Groups > Geospatial I downloaded the Map of Wind Farms data as a .csv from http://en.openei.org/wiki/Map_of_Wind_Farms/Data. The downloaded data contains the latitude and longitude values in a single column. ArcMap requires separate fields for lat/long. Also, there is a strange character at the end of the coordinate values, °. It looks like this might be due to using the degree symbol? Will this cause an issue when attempting to import the downloaded data into ESRI ArcMap software? Thanks for any guidance you can provide! Submitted by Scourer on 10 September, 2013 - 09:40 1 answer Points: 1 Hi- Yes, you are correct with determining why the ° characters appear in the CSV. This is an artifact of transforming the coordinates to values for the

337

(Smart) Look-Ahead Arc Consistency and the Pursuit of CSP Tractability  

E-Print Network [OSTI]

(Smart) Look-Ahead Arc Consistency and the Pursuit of CSP Tractability Hubie Chen 1 and V#19. The constraint satisfaction problem (CSP) can be formu- lated as the problem of deciding, given a pair (A; B) of relational struc- tures, whether or not there is a homomorphism from A to B. Although the CSP is in general

Dalmau, Victor

338

Volatile abundances in submarine glasses from the North Fiji and Lau back-arc basins  

SciTech Connect (OSTI)

Glasses from submarine lavas of the North Fiji and lau back-arc basins were analyzed by high-temperature mass spectrometry for volatiles. Abundances for H{sub 2}O, Cl, F, S and CO{sub 2} in glasses ranging in composition from depleted, primitive MORB to enriched, transitional tholeiites are reported. The samples divide into three groups based on K{sub 2}O vs. H{sub 2}O, Ba/Zr vs. H{sub 2}O and K{sub 2}O/H{sub 2}O vs. P{sub 2}O{sub 5}/H{sub 2}O variation diagrams. At similar Mg No., the least evolved samples studied are nearly identical to N-type MORB in H{sub 2}O abundances but show Cl contents enriched by a factor of 5. More enriched samples, classified as back-arc basin basalts (BABB) on the basis of major/trace elements and isotopes, are not as hydrous (at similar Mg No.) as those from the Mariana and East Scotia Sea back-arc basins. The data indicate that not all back-arc basins erupt lavas with the distinct volatile and other elemental characteristics of lavas from the Mariana Trough and Scotia Sea.

Aggrey, K.E.; Muenow, D.W.; Sinton, J.M. (Univ. of Hawaii, Honolulu (USA))

1988-10-01T23:59:59.000Z

339

An interchangeable-cathode vacuum arc plasma source David K. Olson,a  

E-Print Network [OSTI]

design based on metal vapor vacuum arc MeVVA concepts is employed as a plasma source for a study of a 7 using a boron-carbide disk as the cathode target. The design is simplified from typical designs with a proton beam. We create our 7 Be on the surface of a sample of enriched boron carbide. Because 7

Hart, Gus

340

Measurement and finite element analysis of temperature distribution in arc welding process  

Science Journals Connector (OSTI)

This presentation describes both the experimental measurement and finite element analysis used to study the temperature distribution during a metal inert gas (MIG) welding process, including the cooling down period. Welding was carried out on ... Keywords: FEA, MIG welding, arc welding, cracking, finite element analysis, metal inert gas welding, residual stress, simulation, temperature distribution, weldment temperature

C. K. Lee; J. Candy; C. P. H. Tan

2004-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

High emissivity coatings on titanium alloy prepared by micro-arc oxidation for high temperature application  

Science Journals Connector (OSTI)

Micro-arc oxidation coatings were prepared on Ti6Al4V alloy in...3PO4-based electrolyte with different additives such as FeSO4, Co(CH3COO)2, Ni(CH3COO)2, and K2ZrF6. The composition, structure, surface morphology...

H. Tang; Q. Sun; C. G. Yi; Z. H. Jiang; F. P. Wang

2012-03-01T23:59:59.000Z

342

Convection in Arc Weld Pools Electromagnetic and surface tension forces are shown to  

E-Print Network [OSTI]

Convection in Arc Weld Pools Electromagnetic and surface tension forces are shown to dominate flow tension forces. It is shown that the electromag- netic and surface tension forces domi- nate the flow by experimental measurements of segrega- tion in the weld pool. It is also shown that the surface tension driven

Eagar, Thomas W.

343

Model of Phosphorus Precipitation and Crystal Formation in Electric Arc Furnace Steel Slag Filters  

Science Journals Connector (OSTI)

Model of Phosphorus Precipitation and Crystal Formation in Electric Arc Furnace Steel Slag Filters ... Phosphorus is generally the limiting nutrient in freshwater systems and its discharge from wastewaters favors eutrophication. ... (1) Stricter regulations for phosphorus discharges to smaller treatment plants creates a need for the development of new and extensive (requiring minimal operation) treatment technologies. ...

Dominique Claveau-Mallet; Scott Wallace; Yves Comeau

2011-12-30T23:59:59.000Z

344

The problem of the burning of an electric arc in a stream of gas  

Science Journals Connector (OSTI)

A one-dimensional heat-conduction equation is analyzed for the positive column of an arc discharge in a lateral gas flow (V?J). Two discharge burning regimes are found for the same parameters (E and V). The cr...

V. L. Goryachev; A. D. Lebedev

1967-10-01T23:59:59.000Z

345

Simple Method of Preparing Graphene Flakes by an Arc-Discharge Method  

Science Journals Connector (OSTI)

Simple Method of Preparing Graphene Flakes by an Arc-Discharge Method ... It is noteworthy that graphene can be doped with boron and nitrogen by carrying out the electric discharge in the presence of B2H6 and pyridine, respectively. ...

K. S. Subrahmanyam; L. S. Panchakarla; A. Govindaraj; C. N. R. Rao

2009-02-20T23:59:59.000Z

346

Effects of induced flow on the depths of active back-arc basins  

E-Print Network [OSTI]

The depth of active back-arc basins, younger than 10 Ma is correlated to the angle of subduction, in that the deepest basins are associated with steep angles of subduction, and the shallowest to small angles of subduction. A two-dimensional comer...

Tomlins, Robynn Lee

2012-06-07T23:59:59.000Z

347

UWB radar technique for arc detection in coaxial cables and waveguides  

SciTech Connect (OSTI)

As spread spectrum technology has revolutionized the communications industry, Ultra Wide Band (UWB) technology is dramatically improving radar performances. These advanced signal processing techniques have been adapted to coaxial cables and waveguides to provide new features and enhanced performance on arc detection. UWB signals constituted by a sequence of chips (properly chosen to reduce side lobes and to improve detection accuracy) are transmitted along the transmission lines at a specified Pulse Repetition Frequency (PRF) and their echoes are received by means of directional couplers. The core of the receiver is an ultra high-speed correlator implemented in a Digital Signal Processor (DSP). When a target (arc) is detected, its position and its 'radar cross section' are calculated to be able to provide the arc position along the transmission line and to be able to classify the type of detected arc. The 'background scattering' is routinely extracted from the received signal at any pulse. This permits to be resilient to the background structure of transmission lines (bends, junctions, windows, etc.). Thanks to the localization feature, segmentation is also possible for creating sensed and non-sensed zones (for example, to be insensitive to antenna load variations)

Maggiora, R.; Salvador, S. [Politecnico di Torino, Department of Electronics, Torino (Italy)

2009-11-26T23:59:59.000Z

348

IVSS-2005-ARC-04 Intelligent Vehicle Based Architecture for Real-Time Monitoring  

E-Print Network [OSTI]

in cars for various other applications like inertial guidance systems, and crash detection for air- bag. 59 #12;ACOUSTIC WAVES OF RESPIRATORY SYSTEM DETECTING SENSOR A number of statistical measuresIVSS-2005-ARC-04 Intelligent Vehicle Based Architecture for Real-Time Monitoring of Soldiers

Mahmud, Syed Masud

349

Submarine venting of liquid carbon dioxide on a Mariana Arc volcano  

E-Print Network [OSTI]

Submarine venting of liquid carbon dioxide on a Mariana Arc volcano John Lupton NOAA/Pacific Marine hydrothermal fluids, it is rarely found in the form of CO2 liquid. Here we report the discovery of an unusual CO2-rich hydrothermal system at 1600-m depth near the summit of NW Eifuku, a small submarine volcano

Chadwick, Bill

350

State law equation of a real gas and simulation of electrical arc/gas flow interaction  

Science Journals Connector (OSTI)

Modeling of gas movements in a circuit breaker arc chamber requires an accurate knowledge of thermodynamic functions. The proposed method gives a simplified form of the law of state, in close agreement with the tables. This law has been implemented in the NS2 code developed at Merlin Gerin, France. This code allows detailed investigation of gas flows in circuit breakers.

P Chevrier; J Maftoul

1993-01-01T23:59:59.000Z

351

The Integrated Use of EMME/2 and Arc/Info -Practice in Lyon County, Minnesota  

E-Print Network [OSTI]

maps for these software are very difficult to find. The Geographic Information System (GIS), like Arc in a systematic way. Much effort has been invested in building GIS map databases at city, county and state level in recent years so we can get a digitized map in GIS format easily from the Internet. But the GIS software

Levinson, David M.

352

On the time–scales of magmatism at island–arc volcanoes  

Science Journals Connector (OSTI)

...absent. Numerous studies in the Cascades, Tonga and Vanuatu have consistently...shallow mantle melting under the Cascades volcanoc arc. Geology 29...Vergniolle, S. 1989 Pressure, gas content and eruption periodicity...high-pressure experiments and natural rocks. J. Volcanol. Geotherm...

2002-01-01T23:59:59.000Z

353

How do I display the Map of Wind Farms csv coordinates in ArcMap software?  

Open Energy Info (EERE)

How do I display the Map of Wind Farms csv coordinates in ArcMap software? How do I display the Map of Wind Farms csv coordinates in ArcMap software? Home > Groups > Geospatial I downloaded the Map of Wind Farms data as a .csv from http://en.openei.org/wiki/Map_of_Wind_Farms/Data. The downloaded data contains the latitude and longitude values in a single column. ArcMap requires separate fields for lat/long. Also, there is a strange character at the end of the coordinate values, °. It looks like this might be due to using the degree symbol? Will this cause an issue when attempting to import the downloaded data into ESRI ArcMap software? Thanks for any guidance you can provide! Submitted by Scourer on 10 September, 2013 - 09:40 1 answer Points: 1 Hi- Yes, you are correct with determining why the ° characters appear in the

354

Effect of Electric Arc Furnace Bag House Dust on Concrete Durability Researcher: Fahad Al-Mutlaq  

E-Print Network [OSTI]

Effect of Electric Arc Furnace Bag House Dust on Concrete Durability Researcher: Fahad Al billions of dollars annually. While steel is normally protected from corrosion in concrete by a passive of the effects of addition of Bag House Dust (BHD) on aspects of concrete durability. BHD is a fine powder

Birmingham, University of

355

SCALED ELECTRON MODEL OF A DOGBONE MUON RLA WITH MULTI-PASS ARCS  

SciTech Connect (OSTI)

The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected at the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available at CEBAF 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it straightforward to implement. In this report, we have shown first of all that measuring the energy spectrum of the fast neutrons in the liquid scintillators allows one to distinguish the two chemical forms of plutonium. In addition, combining this information with the Feynman 2-neutron and 3-neutron correlations allows one to extract the {alpha}-ratio without explicitly knowing the multiplication. Given the {alpha}-ratio one can then extract the multiplication as well as the {sup 239}Pu and {sup 240}Pu masses directly from the moment equations.

Kevin Beard, Rolland Johnson, Vasiliy Morozov, Yves Roblin, Andrew Hutton, Geoffrey Krafft, Slawomir Bogacz

2012-07-01T23:59:59.000Z

356

Optimized Hybrid Megavoltage-Kilovoltage Imaging Protocol for Volumetric Prostate Arc Therapy  

SciTech Connect (OSTI)

Purpose: To develop a real-time prostate position monitoring technique for modern arc radiotherapy through novel use of cine-megavoltage (MV) imaging, together with as-needed kilovoltage (kV) imaging. Methods and Materials: We divided the task of monitoring the intrafraction prostate motion into two steps for rotational deliveries: to detect potential target motion beyond a predefined threshold using MV images from different viewing angles by taking advantage of gantry rotation during arc therapy and to verify the displacement and determine whether intervention is needed using fiducial/tumor position information acquired from combined MV-kV imaging (by turning on the kV imager). A Varian Trilogy linear accelerator with an onboard kV imager was used to examine selected typical trajectories using a four-dimensional motion phantom. The performance of the algorithm was evaluated using phantom measurements and computer simulation for 536 Calypso-measured tracks from 17 patients. Results: Fiducial displacement relative to the MV beam was limited to within a range of 3 mm 99.9% of the time with <1 mm accuracy. On average, only {approx}0.5 intervention per arc delivery was needed to achieve this level of accuracy. Compared with other fluoroscopy-based tracking techniques, kV use was significantly reduced to an average of <15 times per arc delivery. Conclusion: By focusing the attention on detecting predefined abnormal motion (i.e., 'failure' detection) and using the inherent mechanism of gantry rotation during arc radiotherapy, the current approach provides high confidence regarding the prostate position in real time without the unwanted overhead of continuous or periodic kV imaging.

Liu Wu; Wiersma, Rodney D. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Xing Lei, E-mail: lei@stanford.ed [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States)

2010-10-01T23:59:59.000Z

357

518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Plasma Dynamics During Breakdown in  

E-Print Network [OSTI]

, lamp, modeling, plasma. METAL halide arc lamps are widely used sources of in- door and large area plasma hydrodynamics model was used to investigate breakdown in metal halide lamp. Images depicting518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Plasma Dynamics During

Kushner, Mark

358

Preparation of Ag–Fe-decorated single-walled carbon nanotubes by arc discharge and their antibacterial effect  

Science Journals Connector (OSTI)

A simple one-step approach for the preparation of Ag–Fe-decorated single-walled carbon nanotubes (Ag–Fe/SWCNTs) by DC hydrogen arc discharge is presented in this article. The growth of SWCNTs and the attachmen...

Xing Liu; Liming Yu; Feng Liu; Leimei Sheng; Kang An…

2012-08-01T23:59:59.000Z

359

Preparation of narrow band gap V2O5/TiO2 composite films by micro-arc oxidation  

Science Journals Connector (OSTI)

V2O5/TiO2...composite films were prepared on pure titanium substrates via micro-arc oxidation (MAO) in electrolytes consisting of NaVO3. Their morphology and elements were characterized by scanning electron micro...

Qiang Luo; Xin-wei Li; Qi-zhou Cai…

2012-11-01T23:59:59.000Z

360

Effects of micro-arc oxidation coating on corrosion behavior of Mg-Y-Zn in simulated body fluid  

Science Journals Connector (OSTI)

The application of magnesium and its alloy as degradable biomaterials is mainly confined due to its high degradation rate in physiological environment. This research focused on the effects of micro-arc oxidation ...

Tian-feng Lu ???; Kai-yang Yin ???…

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Mineralized and osteoid tissue from dental pulp stem cells on micro-arc oxidation titanium in vitro  

Science Journals Connector (OSTI)

The presence of insufficient bone volume affects the implant healing and success. The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells (DPSCs) on micro-arc oxidation (MAO) titanium ...

Yi Huang ? ?; Ting Chang ? ?; Cheng Yang ? ?…

2012-08-01T23:59:59.000Z

362

Micro arc oxidation and electrophoretic deposition effect on damping and sound transmission characteristics of AZ31B magnesium alloy  

Science Journals Connector (OSTI)

Micro arc oxidation (MAO) and electrophoretic deposition (EPD)...L ST) is improved in the stiffness control stage of the sound transmission verse frequency curve. To the samples by electrophoresis...

Zhi Luo ??; Zhi-yong Hao ???; Bai-ling Jiang ???…

2014-09-01T23:59:59.000Z

363

Effect of Micro-arc Oxidation Time on the Ca-P Coating Layer Properties Formed on Commercially Pure Titanium  

Science Journals Connector (OSTI)

In the present study, the Ca-P coating layer on commercially pure titanium was fabricated using Micro-arc oxidation (MAO) method in electrolyte for osteointegrative ... size of micropores have increased with an i...

P. Katekaew; W. Veerasai; A. Aeimbhu

2010-01-01T23:59:59.000Z

364

Influence of Electrolyte Chemistry on Morphology and Corrosion Resistance of Micro Arc Oxidation Coatings Deposited on Magnesium  

Science Journals Connector (OSTI)

In the present work, micro arc oxidation (MAO) coatings were synthesized on magnesium...2SiO3), potassium hydroxide (KOH), and sodium aluminate (NaAlO2). The resultant coatings were subjected to coating thickness...

L. Rama Krishna; G. Poshal; G. Sundararajan

2010-12-01T23:59:59.000Z

365

Thermal calculation of combined transpiration-liquid cooling of discharge-chamber walls of an electric-arc heater  

Science Journals Connector (OSTI)

The article presents a theoretical calculation of the temperature profiles and optimal thicknesses of porous and solid cooled walls, which provide a steady-state operation of an electric-arc heater with transpira...

G. L. Dobroedov; V. I. Krylovich

1970-03-01T23:59:59.000Z

366

Effect of metal oxide and oxygen on the growth of single-walled carbon nanotubes by electric arc discharge  

Science Journals Connector (OSTI)

The effect of oxygen on the growth of single-walled carbon nanotubes was studied with Ni–Co alloy powder as catalyst under helium atmosphere of 500 Torr by electric arc discharge. The oxygen included in nickel or...

Delong He; Yongning Liu; Tingkai Zhao; Jiewu Zhu…

2008-03-01T23:59:59.000Z

367

Development of an ArcGIS interface and design of a geodatabase for the soil and water assessment tool  

E-Print Network [OSTI]

the Geodatabase object model and concepts from hydrological data models such as ArcHydro. It also incorporates uncertainty analysis on the process of modeling. This interface aims to further direct communication and integration with other hydrologic models...

Valenzuela Zapata, Milver Alfredo

2004-09-30T23:59:59.000Z

368

Correlation between Microstructure and Mechanical Properties of TiC Films Produced by Vacuum arc Deposition and Reactive Magnetron Sputtering  

E-Print Network [OSTI]

and mechanical properties of TiC films produced by vacuumstudied the synthesis of TiC films by vacuum arc depositionproduced a broad range of TiC x film compositions. In both

Monteiro, O.R.; Delplancke-Ogletree, M.P.; Winand, R.; Brown, I.G.

1999-01-01T23:59:59.000Z

369

Nanoparticle suspension preparation using the arc spray nanoparticle synthesis system combined with ultrasonic vibration and rotating electrode  

Science Journals Connector (OSTI)

This study aims to investigate the use of a new nanoparticle preparation method, i.e., the arc spray nanoparticle synthesis system (ASNSS) combined with ultrasonic...2 nanoparticle suspension. For the proposed ne...

H. Chang; T.T. Tsung; Y.C. Yang; L.C. Chen…

2005-09-01T23:59:59.000Z

370

Bounds for the moduli of continuity for conformal mappings of domains near their accessible boundary arcs  

SciTech Connect (OSTI)

The paper presents bounds for the moduli of continuity {omega}(f, G-bar ,{delta}) of conformal mappings w=f(z) of a bounded simply connected domain G with an arbitrary Jordan boundary onto a bounded simply connected domain with an arbitrary Jordan boundary, the 'quality' of boundaries being taken into account. For a Jordan curve (simple arc or a closed contour), its quality is characterized in general by its modulus of oscillation, and if it has finite length, by a more sensitive modulus of rectifiability-these purely metric concepts were introduced by the author in 1996. Theorems on the behaviour of conformal mappings of simply connected domains of arbitrary nature near open accessible boundary arcs are established. Bibliography: 18 titles.

Dolzhenko, Evgenii P [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

2011-12-31T23:59:59.000Z

371

Graphene layer growth on silicon substrates with nickel film by pulse arc plasma deposition  

SciTech Connect (OSTI)

Carbon layer has been grown on a Ni/SiO{sub 2}/Si(111) substrate under high vacuum pressure by pulse arc plasma deposition. From the results of Raman spectroscopy for the sample, it is found that graphene was formed by ex-situ annealing of sample grown at room temperature. Furthermore, for the sample grown at high temperature, graphene formation was shown and optimum temperature was around 1000 Degree-Sign C. Transmission electron microscopy observation of the sample suggests that the graphene was grown from step site caused by grain of Ni film. The results show that the pulse arc plasma technique has the possibility for acquiring homogenous graphene layer with controlled layer thickness.

Fujita, K.; Banno, K.; Aryal, H. R.; Egawa, T. [Research Center for Nano-Device and System, Nagoya Institute of Technology, Gokiso-cho, Showa-Ku, Nagoya 466-8555 (Japan)

2012-10-15T23:59:59.000Z

372

Schlieren technique applied to the arc temperature measurement in a high energy density cutting torch  

SciTech Connect (OSTI)

Plasma temperature and radial density profiles of the plasma species in a high energy density cutting arc have been obtained by using a quantitative schlieren technique. A Z-type two-mirror schlieren system was used in this research. Due to its great sensibility such technique allows measuring plasma composition and temperature from the arc axis to the surrounding medium by processing the gray-level contrast values of digital schlieren images recorded at the observation plane for a given position of a transverse knife located at the exit focal plane of the system. The technique has provided a good visualization of the plasma flow emerging from the nozzle and its interactions with the surrounding medium and the anode. The obtained temperature values are in good agreement with those values previously obtained by the authors on the same torch using Langmuir probes.

Prevosto, L.; Mancinelli, B. [Departamento Ing. Electromecanica, Grupo de Descargas Electricas, Universidad Tecnologica Nacional, Regional Venado Tuerto, Las Heras 644, Venado Tuerto, Santa Fe 2600 (Argentina); Artana, G. [Departamento Ing. Mecanica, Laboratorio de Fluidodinamica, Facultad de Ingenieria (UBA), Paseo Colon 850 (C1063ACV), Buenos Aires (Argentina); Kelly, H. [Departamento de Fisica, Instituto de Fisica del Plasma (CONICET), Facultad de Ciencias Exactas y Naturales (UBA), Ciudad Universitaria Pab. I, Buenos Aires 1428 (Argentina)

2010-01-15T23:59:59.000Z

373

Large-scale purification of single-wall carbon nanotubes prepared by electric arc discharge  

Science Journals Connector (OSTI)

High-yield single-wall carbon nanotubes (SWNTs) have been mass-produced by dc arc discharge evaporation of a carbon electrode including 1 at.% Fe catalyst in hydrogen mixed gas [i.e., H2–inert gas (Ne, Ar, Kr, Xe), or H2–N2]. The as-grown \\{SWNTs\\} have high-crystallinity due to the high temperature of arc plasma, and the coexisting Fe catalyst nanoparticles are embedded in very thin amorphous carbon because of the in situ etching effects of hydrogen. A macroscale purification technique, which is a whole liquid-phase purification process, first reflux treatment in H2O2 solution and then rinsing with hydrochloric acid, has been developed to eliminate the coexisting Fe catalyst nanoparticles and obtain \\{SWNTs\\} with purity higher than 90 at.%.

Xinluo Zhao; Masato Ohkohchi; Sakae Inoue; Tomoko Suzuki; Takenori Kadoya; Yoshinori Ando

2006-01-01T23:59:59.000Z

374

Exhaust Gas Fuel Reforming of Diesel Fuel by Nonthermal Arc Discharge for NOx Trap Regeneration Application  

Science Journals Connector (OSTI)

Exhaust Gas Fuel Reforming of Diesel Fuel by Nonthermal Arc Discharge for NOx Trap Regeneration Application ... It has been demonstrated that low current arc discharges are highly nonhomogenous. ... In the second case, which corresponds to the most favorable one, assuming (i) a 100 kW car engine thermal power (i.e., 40 kW mechanical power), (ii) that the plasma will treat only a small fraction of the exhaust gas (typically 3.5%), (iii) that the plasma will operate under a cycling operating mode, and (iv) an 80% efficiency for the onboard production of electricity from the car engine, one can estimate that the electric power needed to run the plasma will be around 2.2% of the engine power only during 12 s every 11 km (6.8 miles), that is, 12 s every 6 min assuming a 110 km·h?1 (68 mph) average car velocity. ...

Alexandre Lebouvier; Franc?ois Fresnet; Fre?de?ric Fabry; Vale?rie Boch; Vandad Rohani; Franc?ois Cauneau; Laurent Fulcheri

2011-02-03T23:59:59.000Z

375

Spectroscopy peculiarities of thermal plasma of electric arc discharge between electrodes with Zn admixtures  

Science Journals Connector (OSTI)

Abstract Plasma of the free burning electric arc between Ag–SnO2–ZnO composite electrodes as well as brass electrodes were investigated. The plasma temperature distributions were obtained by Boltzmann plot method involving Cu I, Ag I or Zn I spectral line emissions. The electron density distributions were obtained from the width and from absolute intensity of spectral lines. The laser absorption spectroscopy was used for measurement of copper atom concentration in plasma. Plasma equilibrium composition was calculated using two independent groups of experimental values (temperature and copper atom concentration, temperature and electron density). It was found that plasma of the free burning electric arc between brass electrodes is in local thermodynamical equilibrium. The experimental verification of the spectroscopic data of Zn I spectral lines was carried out.

R.V. Semenyshyn; A.N. Veklich; I.L. Babich; V.F. Boretskij

2014-01-01T23:59:59.000Z

376

Synthesis of multiwall carbon nanotubes by electric arc discharge in liquid environments  

Science Journals Connector (OSTI)

This work reports the experimental results from the production of multiwall carbon nanotubes (MWCN) synthesized by an electric arc discharge performed in liquid environments between pure graphite electrodes. Both liquid nitrogen and deionised water were suitable for a successful synthesis of this form of carbon aggregation. We report a successful synthesis of MWCN by arc discharge submerged in deionised water. Electron microscopy observations of both the reaction products and the surface of the as-synthesized raw material showed the presence of structural degradation of the MWCN, which probably operates after their growth at the cathode. The degradation is tentatively ascribed to a combination of overheating and high current density experienced by the as-synthesized MWNT, which can be caused by the loose structure of the as-deposited material. The damage appeared to be less severe in water environments, probably owing to the better cooling capacity of water relative to liquid nitrogen.

Marco Vittori Antisari; Renzo Marazzi; Radenka Krsmanovic

2003-01-01T23:59:59.000Z

377

A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)  

SciTech Connect (OSTI)

High power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in this review, an overview is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.

Anders, Andre

2014-08-17T23:59:59.000Z

378

Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication  

DOE Patents [OSTI]

A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing. 8 figs.

Brown, I.G.; MacGill, R.A.; Galvin, J.E.; Ogletree, D.F.; Salmeron, M.

1998-11-24T23:59:59.000Z

379

Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication  

DOE Patents [OSTI]

A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing.

Brown, Ian G. (Berkeley, CA); MacGill, Robert A. (Richmond, CA); Galvin, James E. (Emmeryville, CA); Ogletree, David F. (El Cerrito, CA); Salmeron, Miquel (El Cerrito, CA)

1998-01-01T23:59:59.000Z

380

Ion flux from vacuum arc cathode spots in the absence and presence of a magnetic field  

SciTech Connect (OSTI)

Because plasma production at vacuum cathode spots is approximately proportional to the arc current, arc current modulation can be used to generate ion current modulation that can be detected far from the spot using a negatively biased ion collector. The drift time to the ion detector can used to determine kinetic ion energies. A very wide range of cathode materials have been used. It has been found that the kinetic ion energy is higher at the beginning of each discharge and approximately constant after 150 {micro}s. The kinetic energy is correlated with the arc voltage and the cohesive energy of the cathode material. The ion erosion rate has in inverse relation to the cohesive energy, enhancing the effect that the power input per plasma particle correlates with the cohesive energy of the cathode material. The influence of three magnetic field configurations on the kinetic energy has been investigated. Generally, a magnetic field increases the plasma impedance, arc burning voltage, and kinetic ion energy. However, if the plasma is produced in a region of low field strength and streaming into a region of higher field strength, the velocity may decrease due to the mirror effect. A magnetic field can increase the plasma temperature but may reduce the density gradients by preventing free expansion into vacuum. Therefore, depending on the configuration, a magnetic field may increase or decrease the kinetic energy of ions. Additionally, the angular distribution of the ion flux and ion kinetic energy has been investigated in the absence of an external magnetic field. The result can be fitted by a superposition of an isotropic and a cosine distribution.

Anders, Andre; Yushkov, George Yu.

2001-10-02T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
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381

Prevention of covered conductor burndown on distribution circuits - arcing protection devices  

SciTech Connect (OSTI)

The mechanism of covered conductor burndown is discussed in light of experience by the Pennsylvania Power and Light Company (PPandL) on 12-kV distribution circuits. A summary of laboratory test results is given to allow extension of this work to other distribution circuits. Details and early field experience are included on the Arcing Protection Device (APD), selected in an earlier study/sup 1/ as the superior burndown prevention technique.

Lee, R.E. (Pennsylvania Power and Light Co., Allentown, PA); Fritz, D.; Shankle, D.; Stiller, P.

1982-08-01T23:59:59.000Z

382

Self-Organized Networks and Lattice Effects in High Temperature Superconductors II: Fermi Arc Anomalies  

E-Print Network [OSTI]

The self-organized dopant percolative filamentary model, entirely orbital in character (no fictive spins), explains the evolution with doping of Fermi arcs observed by ARPES, including the previously unexplained abrupt transitions in quasiparticle strength observed near optimal doping in cuprate high temperature superconductors. Similarly abrupt transitions are also observed in time-resolved picosecond relaxation spectroscopy at 1.5 eV, and these are explained as well, using no new assumptions and no adjustable parameters.

J. C. Phillips

2006-11-07T23:59:59.000Z

383

Exploring high temperature phenomena related to post-detonation using an electric arc  

SciTech Connect (OSTI)

We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100??s. Samples took the form of a 4??m-thick film deposited onto 8 pairs of 17??m-thick Cu electrodes supported on a 25??m-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO{sub 2}, UC{sub 2}, UCu{sub 5},) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ?2300?K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.

Dai, Z. R., E-mail: dai1@llnl.gov; Crowhurst, J. C.; Grant, C. D.; Knight, K. B.; Tang, V.; Chernov, A. A.; Cook, E. G.; Lotscher, J. P.; Hutcheon, I. D. [Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States)

2013-11-28T23:59:59.000Z

384

Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel  

SciTech Connect (OSTI)

The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated that the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.

Lévesque, D.; Rousseau, G.; Monchalin, J.-P. [National Research Council Canada, Boucherville, QC (Canada); Wanjara, P.; Cao, X. [National Research Council Canada, Montreal, QC (Canada)

2014-02-18T23:59:59.000Z

385

Mechanism of Synthesis of Ultra-Long Single Wall Carbon Nanotubes in Arc Discharge Plasma  

SciTech Connect (OSTI)

In this project fundamental issues related to synthesis of single wall carbon nanotubes (SWNTs), which is relationship between plasma parameters and SWNT characteristics were investigated. Given that among plasma-based techniques arc discharge stands out as very advantageous in several ways (fewer defects, high flexibility, longer lifetime) this techniques warrants attention from the plasma physics and plasma technology standpoint. Both experimental and theoretical investigations of the plasma and SWNTs synthesis were conducted. Experimental efforts focused on plasma diagnostics, measurements of nanostructures parameters, and nanoparticle characterization. Theoretical efforts focused to focus on multi-dimensional modeling of the arc discharge and single wall nanotube synthesis in arc plasmas. It was demonstrated in experiment and theoretically that controlling plasma parameters can affect nanostucture synthesis altering SWNT properties (length and diameter) and leading to synthesis of new structures such as a few-layer graphene. Among clearly identified parameters affecting synthesis are magnetic and electric fields. Knowledge of the plasma parameters and discharge characteristics is crucial for ability to control synthesis process by virtue of both magnetic and electric fields. New graduate course on plasma engineering was introduced into curriculum. 3 undergraduate students were attracted to the project and 3 graduate students (two are female) were involved in the project. Undergraduate student from Historically Black University was attracted and participated in the project during Summer 2010.

Keidar, Michael [George Washington University] [George Washington University

2013-06-23T23:59:59.000Z

386

Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source  

SciTech Connect (OSTI)

The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and hydrogen gas flow rate. Measurements of the pressure in the arc channel show that the flow is well described by Poiseuille flow and that the effective heavy particle temperature is approximately 0.8 eV. Interpretation of the measured I-V data in terms of a one-parameter model shows that the plasma production is proportional to the input power, to the square root of the hydrogen flow rate, and is independent of the channel diameter. The observed scaling shows that the dominant power loss mechanism inside the arc channel is one that scales with the effective volume of the plasma in the discharge channel. Measurements on the plasma output with Thomson scattering confirm the linear dependence of the plasma production on the input power. Extrapolation of these results shows that (without a magnetic field) an improvement in the plasma production by a factor of 10 over where it was in van Rooij et al. [Appl. Phys. Lett. 90, 121501 (2007)] should be possible.

Vijvers, W. A. J.; Gils, C. A. J. van; Goedheer, W. J.; Meiden, H. J. van der; Veremiyenko, V. P.; Westerhout, J.; Lopes Cardozo, N. J.; Rooij, G. J. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Schram, D. C. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2008-09-15T23:59:59.000Z

387

Dense molecular globulettes and the dust arc towards the runaway O star AE Aur (HD 34078)  

E-Print Network [OSTI]

Some runaway stars are known to display IR arc-like structures around them, resulting from their interaction with surrounding interstellar material. The properties of these features as well as the processes involved in their formation are still poorly understood. We aim at understanding the physical mechanisms that shapes the dust arc observed near the runaway O star AEAur (HD34078). We obtained and analyzed a high spatial resolution map of the CO(1-0) emission that is centered on HD34078, and that combines data from both the IRAM interferometer and 30m single-dish antenna. The line of sight towards HD34078 intersects the outer part of one of the detected globulettes, which accounts for both the properties of diffuse UV light observed in the field and the numerous molecular absorption lines detected in HD34078's spectra, including those from highly excited H2 . Their modeled distance from the star is compatible with the fact that they lie on the 3D paraboloid which fits the arc detected in the 24 {\\mu}m Spitz...

Gratier, P; Boissé, P; Cabrit, S; Lesaffre, P; Gerin, M; Forêts, G Pineau des

2014-01-01T23:59:59.000Z

388

Arc plasma generator of atomic driver for steady-state negative ion source  

SciTech Connect (OSTI)

The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB{sub 6} cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

Ivanov, A. A.; Belchenko, Yu. I.; Davydenko, V. I. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation) [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Ivanov, I. A.; Kolmogorov, V. V.; Listopad, A. A., E-mail: a.a.listopad@inp.nsk.su; Mishagin, V. V.; Shulzhenko, G. I. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)] [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Putvinsky, S. V.; Smirnov, A. [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States)] [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States)

2014-02-15T23:59:59.000Z

389

Implementing RapidArc into clinical routine: A comprehensive program from machine QA to TPS validation and patient QA  

SciTech Connect (OSTI)

Purpose: With the increased commercial availability of intensity modulated arc therapy (IMAT) comes the need for comprehensive QA programs, covering the different aspects of this newly available technology. This manuscript proposes such a program for the RapidArc (RA) (Varian Medical Systems, Palo Alto) IMAT solution. Methods: The program was developed and tested out for a Millennium120 MLC on iX Clinacs and a HighDefinition MLC on a Novalis TX, using a variety of measurement equipment including Gafchromic film, 2D ion chamber arrays (Seven29 and StarCheck, PTW, Freiburg, Germany) with inclinometer and Octavius phantom, the Delta4 systam (ScandiDos, Uppsala, Sweden) and the portal imager (EPID). First, a number of complementary machine QA tests were developed to monitor the correct interplay between the accelerating/decelerating gantry, the variable dose rate and the MLC position, straining the delivery to the maximum allowed limits. Second, a systematic approach to the validation of the dose calculation for RA was adopted, starting with static gantry and RA specific static MLC shapes and gradually moving to dynamic gantry, dynamic MLC shapes. RA plans were then optimized on a series of artificial structures created within the homogeneous Octavius phantom and within a heterogeneous lung phantom. These served the double purpose of testing the behavior of the optimization algorithm (PRO) as well as the precision of the forward dose calculation. Finally, patient QA on a series of clinical cases was performed with different methods. In addition to the well established in-phantom QA, we evaluated the portal dosimetry solution within the Varian approach. Results: For routine machine QA, the ''Snooker Cue'' test on the EPID proved to be the most sensitive to overall problem detection. It is also the most practical one. The ''Twinkle'' and ''Sunrise'' tests were useful to obtain well differentiated information on the individual treatment delivery components. The AAA8.9 dose calculations showed excellent agreement with all corresponding measurements, except in areas where the 2.5 mm fixed fluence resolution was insufficient to accurately model the tongue and groove effect or the dose through nearly closed opposing leafs. Such cases benefited from the increased fluence resolution in AAA10.0. In the clinical RA fields, these effects were smeared out spatially and the impact of the fluence resolution was considerably less pronounced. The RA plans on the artificial structure sets demonstrated some interesting characteristics of the PRO8.9 optimizer, such as a sometimes unexpected dependence on the collimator rotation and a suboptimal coverage of targets within lung tissue. Although the portal dosimetry was successfully validated, we are reluctant to use it as a sole means of patient QA as long as no gantry angle information is embedded. Conclusions: The all-in validation program allows a systematic approach in monitoring the different levels of RA treatments. With the systematic approach comes a better understanding of both the capabilities and the limits of the used solution. The program can be useful for implementation, but also for the validation of major upgrades.

Van Esch, Ann; Huyskens, Dominique P.; Behrens, Claus F.; Samsoee, Eva; Sjoelin, Maria; Bjelkengren, Ulf; Sjoestroem, David; Clermont, Christian; Hambach, Lionel; Sergent, Francois [7Sigma, QA-team in Radiotherapy Physics, 3150 Tildonk, Belgium and Department of Radiotherapy, Clinique Ste. Elisabeth, 5000 Namur (Belgium); Department of Oncology, Division of Radiophysics, Copenhagen University Hospital, 2730 Herlev (Denmark); Department of Radiotherapy, Clinique Ste. Elisabeth, 5000 Namur (Belgium)

2011-09-15T23:59:59.000Z

390

Effect of cerium ions in an arc peripheral plasma on the growth of radial single-walled carbon nanotubes  

SciTech Connect (OSTI)

Radial single-walled carbon nanotubes (radial SWCNTs) are formed by using a direct current (dc) arc discharge when carbon and metal atoms are mixed in a gas phase after the vaporization and cooled together in a liquid droplet. Since SWCNTs sprout through the precipitation of saturated carbon atoms from liquid droplets during cooling, a mass synthesis of radial SWCNTs can be achieved when a large number of liquid droplets are generated. In order to understand the effects of arc peripheral plasma parameters (electrons, ions, radical atoms, and molecules) on the growth of radial SWCNTs, the optimum production efficiency of radial SWCNTs is investigated by superimposing a radio-frequency (rf) plasma on the thermal arc plasma and controlling the arc peripheral plasma density. Two parameters--the rf power and the dc potential--of the rf electrode, which is equipped above 20 mm from the center of an arc-discharge point, are changed with the constant He pressure (200 Torr), dc arc current (75 A), and power (2000 W). The production yield of radial SWCNTs is found to be enhanced under the condition of the rf power of 100 W and the dc component of the rf electrode voltage of -22 V, revealing that the optimum ion flux and ion bombardment energy are important key parameters for the formation of radial SWCNTs.

Sato, Y.; Motomiya, K.; Jeyadevan, B.; Tohji, K.; Sato, G.; Ishida, H.; Hirata, T.; Hatakeyama, R. [Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579 (Japan); Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan)

2005-11-01T23:59:59.000Z

391

Biosystem Dynamics & Design | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Biosystem Dynamics & Design Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems Biosystem Dynamics &...

392

Influence of Peroxynitrite in Gliding Arc Discharge Treatment of Alizarin Red S and Postdischarge Effects  

Science Journals Connector (OSTI)

(15-17) Some nonthermal plasma techniques, such as corona,(18, 19) dielectric barrier discharge (DBD),(20) or gliding arc discharges (GAD) belong to these AOPs: they burn at atmospheric pressure in conditions halfway from thermal and nonthermal plasmas, since electrons and heavy particles are not fully thermalized as they are in thermal plasmas. ... Technical cost evaluation takes into account the reagents used and electricity consumption. ... Kamgang Youbi, G.; Herry, J.-M.; Bellon-Fontaine, M.-N.; Brisset, J.-L.; Doubla, A.; Naïtali, M.Evidence of the temporal post-discharge decontamination of bacteria by gliding electric discharges: Application to Hafnia alvei Appl. ...

D. R. Merouani; F. Abdelmalek; M. R. Ghezzar; A. Semmoud; A. Addou; J. L. Brisset

2012-12-24T23:59:59.000Z

393

Shapes of Spectral Lines of Nonuniform Plasma of Electric Arc Discharge Between Copper Electrodes  

SciTech Connect (OSTI)

The radial profiles of the temperature and electron density in the plasma of the free burning electric arc between copper electrodes are studied by optical spectroscopy techniques. The electron density and the temperature in plasma as initial parameters were used in the calculation of the plasma composition in local thermodynamic equilibrium (LTE) assumption. We used the Saha's equation for copper, nitrogen and oxygen, dissociation equation for nitrogen and oxygen, the equation of plasma electrical neutrality and Dalton's law as well. So, it would be possible to determine the amounts of metal vapours in plasma.

Babich, Ida L.; Boretskij, Viacheslav F.; Veklich, Anatoly N. [Radiophysics Faculty, Taras Shevchenko Kyiv National University, 64, Volodymyrs'ka Str., Kyiv 01033 (Ukraine)

2007-09-28T23:59:59.000Z

394

Influence of discharge gap on the discharge stability in a short vacuum arc ion source  

SciTech Connect (OSTI)

The influence of the discharge gap between cathode and anode on the discharge stability in a short vacuum arc (SVA) ion source is presented in this paper. Planar cathode and cylindrical hollow anode made of titanium are investigated. There is a great need in present accelerator injection research for SVA source to produce the small deviation of the ion current beam. Current research shows that increasing the short discharge gap can reduce the level of ion current deviation and ion charge deviation from 29% and 31% to 15% and 17%, respectively. A microplasma plume generation mechanism in SVA and scanning electron microscopic results can be used to explain this interesting phenomenon.

Chen, L. [Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Zhang, G. L.; Jin, D. Z.; Dai, J. Y. [Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Yang, L. [Institute of Nuclear Science and Technology, Louzhou University, Lanzhou, Gansu 730000 (China)

2012-02-15T23:59:59.000Z

395

Low Cost Arc Fault Detection and Protection for PV Systems: January 30, 2012 - September 30, 2013  

SciTech Connect (OSTI)

Final report for Tigo Energy Incubator project. The specific objective of this 18-month research effort was to develop an off-the-shelf arc-fault detector. The starting point of the project was a prototype detector that was constructed using discrete components and laboratory equipment. An intermediate objective was to build a technically viable detector using programmable components in the detector circuitry. The final objective was to build a commercially viable detector by reducing the cost of the circuitry through the use of more sophisticated programmable components and higher levels of integration.

McCalmont, S.

2013-10-01T23:59:59.000Z

396

Surface preparation effects on GTA (gas tungsten arc) weld penetration in JBK-75 stainless steel  

SciTech Connect (OSTI)

The results of a study are reported here on the effects of surface preparation on the shape of GTA welds on JBK-75, an austenitic precipitation hardenable stainless steel similar to A286. Minor changes in surface (weld groove) preparation produced substantial changes in the penetration characteristics and welding behavior of this alloy. Increased and more consistent weld penetration (higher d/w ratios) along with improved arc stability and less arc wander result from wire brushing and other abrasive surface preparations, although chemical and machining methods did not produce any improvement in penetration. Abrasive treatments roughen the surface, increase the surface area, and increase the surface oxide thickness. The increased weld d/w ratio is attributed to oxygen added to the weld pool from the surface oxide on the base metal. The added oxygen alters the surface-tension driven fluid flow pattern in the weld pool. Similar results were observed with changes in filler wire surface oxide thickness, caused by changes in wire production conditions. 15 refs., 14 figs., 4 tabs.

Campbell, R.D.; Heiple, C.R.; Sturgill, P.L.; Robertson, A.M.; Jamsay, R.

1989-01-01T23:59:59.000Z

397

Scale-up analysis and development of gliding arc discharge facility for volatile organic compounds decomposition  

Science Journals Connector (OSTI)

The influences of inlet gas flow rate and reactor configuration on volatile organic compounds (VOCs) decomposition efficiency in a traditional gliding arc (T-GA) facility are studied based on laboratory experiments and numerical simulation. The ratio of the nozzle diameter and the shortest distance of two electrodes should be maintained in a suitable value range to guarantee the decomposition efficiency, which indicates simply enlarging the nozzle inner diameter is not a proper way to raise the T-GA treatment capacity in a fixed supply voltage condition. A developed gliding arc gas discharge (D-GA) reactor based on a modified gas feed system is proposed: small flow rate air goes through the bottom nozzle to process the GA evolution, and high flow rate contaminated gas goes frontal through the plasma region and decomposes. The performances of D-GA reactor in the decomposition of \\{VOCs\\} with relative high gas flow rate, including decomposition efficiency and specific energy consumption, are better than T-GA reactor. D-GA reactor also avoids the drawbacks of the increases of power system amount and electric power consumption in multi-electrode GA system.

Zheng Bo; Jianhua Yan; Xiaodong Li; Yong Chi; Kefa Cen

2008-01-01T23:59:59.000Z

398

Development of high efficiency Versatile Arc Discharge Ion Source at CERN ISOLDE  

SciTech Connect (OSTI)

We report here recent developments of Forced Electron Beam Induced Arc Discharge (FEBIAD) ion sources at the ISOLDE radioactive ion beam facility, hosted at the European Organization for Nuclear Research (CERN). As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5-20 times larger than with the standard ISOLDE FEBIAD ion sources and reach 60% for radon, which allowed the identification at ISOLDE of {sup 229}Rn, an isotope that had never previously been observed in the laboratory. A factor of 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model, which gives precise insights on the processes affecting the ionization, is used to design optimal sources (grouped under the name of VADIS - Versatile Arc Discharge Ion Source) for the different chemical classes of the produced isotopes, as already demonstrated for the noble gases.

Penescu, L.; Catherall, R.; Lettry, J.; Stora, T. [CERN, CH-1211, Geneva 23 (Switzerland)

2010-02-15T23:59:59.000Z

399

Molecular dynamics of shock-wave induced structural changes in silica glasses  

Science Journals Connector (OSTI)

We seek to model the shock wave induced structural changes in silicate glass at the atomic scale. We use both direct shock propagation with nonequilibrium molecular dynamics (NEMD) and bulk simulations in the Hugoniot ensemble to characterize the structure and topology of the shocked glass. Despite the lack of long-range interactions in our model, the close agreement between our structures and those obtained by experimental and simulation studies alike underlines the importance of the role played by first neighbor interactions on the structure of silicate glass. The results obtained from this study show that, in agreement with experimental work, the structure and topology of the shock-induced densified phase is unique in its structure as can be revealed by medium-range order measurements. The modifications include a reduction of the average tetrahedra size and an increase in the proportion of 3–4 and 8–10 membered Si-rings. Application of a Hugoniostat method based on constraint dynamics shows near-perfect agreement with the NEMD results. Besides validating the former method, this opens the prospect of studying shock-induced effects at a fraction of the cost required to run large scale shock simulations while using much more complicated potentials and setups.

F. Barmes; L. Soulard; M. Mareschal

2006-06-16T23:59:59.000Z

400

Optimization of the Ni?Y Catalyst Composition in Bulk Electric Arc Synthesis of Single-Walled Carbon Nanotubes by Use of Near-Infrared Spectroscopy  

Science Journals Connector (OSTI)

Optimization of the Ni?Y Catalyst Composition in Bulk Electric Arc Synthesis of Single-Walled Carbon Nanotubes by Use of Near-Infrared Spectroscopy ... The broad window of acceptable synthetic parameters found in this study suggests that there is an opportunity to scale-up the electric arc (EA) discharge synthesis of SWNTs to the industrial level. ...

M. E. Itkis; D. E. Perea; S. Niyogi; J. Love; J. Tang; A. Yu; C. Kang; R. Jung; R. C. Haddon

2004-07-31T23:59:59.000Z

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Presented in Concord, Conway, Lee & Plymouth by the UNHCE Geospatial Outreach Program ArcGIS Intro Workshops March to June 2012  

E-Print Network [OSTI]

, Plymouth, NH Topics covered: ArcGIS 10 Exploring GIS maps GIS techniques $99 Skill level: Fundamentals maps GIS techniques GIS data maintenance $495 standard, $349 reduced Skill level: Fundamentals Learn; import data into ArcGIS, design maps using layouts phone: 603.862.1029 web: http://gisworkshops.org email

New Hampshire, University of

402

Introduction Basic dynamics  

E-Print Network [OSTI]

Introduction Basic dynamics The Gulf Stream The thermohaline circulation Ocean currents: some Ocean currents: some misconceptions and some dynamics #12;Introduction Basic dynamics The Gulf Stream. Geosciences Ocean currents: some misconceptions and some dynamics #12;Introduction Basic dynamics The Gulf

LaCasce, Joseph H.

403

JOURNAL DE PHYSIQUE CoZZoque C7, suppZ&nent au n07, Tome 40, Juillet 1979, page C7-451 AN INVESTIGATIONOF ARC STARTING ON COLDCATHODES  

E-Print Network [OSTI]

-voltage arc spot mode, with brief(40 micro-sec) re-ignition and de-ignition spikes near current zero electrodes. This arc spot can move about a tungsten surface w i t h scattered oxide surface layers AN INVESTIGATIONOF ARC STARTING ON COLDCATHODES Harald L.Witting. Genera2 Electric Company, Corporate Research

Paris-Sud XI, Université de

404

A numerical study of the supply mode effects on high-pressure mercury discharge lamp dynamic thermal behavior  

SciTech Connect (OSTI)

This paper presents a numerical study of the dynamic behavior of high-pressure mercury discharge lamp as a function of supply mode. Bidimensional time-dependent equations have been solved by using a semi-implicit finite-element code. The model has been developed in the frame of the local thermodynamic equilibrium hypothesis. After validation by using experimental data from the literature, this model was applied to analyze the effects of some key parameters such as frequency for an ac arc current and the ratio cycle parameter for square arc-current wave form on the convective process. The results obtained have been used to analyze the dynamic thermal behavior of high-pressure mercury plasma (pressure equal to 0.3 MPa) working under currents widely different in frequency and wave form.

Kaziz, S.; Ahmed, R. Ben; Araoud, Z.; Gazzah, M.H.; Charrada, K.; Said, R. [EMIR, IPEIM, route de Skanes, 5019 Monastir (Tunisia); FSM, avenue de l'environnement, 5019 Monastir (Tunisia); EMIR, IPEIM, route de Skanes, 5019 Monastir (Tunisia)

2005-06-15T23:59:59.000Z

405

2009 US-Japan Workshop on Advanced Simulation Methods in Plasma Physics Holistic Simulation of Auroral Arcs Formation  

E-Print Network [OSTI]

2009 US-Japan Workshop on Advanced Simulation Methods in Plasma Physics Holistic Simulation convection flow generated in the vicinity of the magnetospheric equator by the solar wind is expected) simulations on the basis of the feedback instability theory attempted to demonstrate the quiet auroral arcs

Ito, Atsushi

406

Exhaust gas fuel reforming of Diesel fuel by non-thermal arc discharge for NOx trap regeneration  

E-Print Network [OSTI]

1 Exhaust gas fuel reforming of Diesel fuel by non- thermal arc discharge for NOx trap regeneration to the reforming of Diesel fuel with Diesel engine exhaust gas using a non-thermal plasma torch for NOx trap Diesel fuel reforming with hal-00617141,version1-17May2013 Author manuscript, published in "Energy

Boyer, Edmond

407

Characterization of ceramic coating on ZK60 magnesium alloy prepared in a dual electrolyte system by micro-arc oxidation  

Science Journals Connector (OSTI)

Micro-arc oxidation (MAO) process was carried out in...2O4 and MgO are the main phases of ceramic coating obtained in the dual electrolyte system. The corrosion rate of coating prepared in the optimized dual elec...

Ze-Xin Wang; Wei-Gang Lv; Jing Chen; Sheng Lu

2013-10-01T23:59:59.000Z

408

Type A Investigation of the Electrical Arc Injury at the Stanford Linear Accelerator Complex on October 11, 2004  

Broader source: Energy.gov [DOE]

On October 11, 2004, at approximately 11:15 am, a subcontractor electrician working at the Stanford Linear Accelerator Center (SLAC) received serious burn injuries requiring hospitalization due to an electrical arc flash that occurred during the installation of a circuit breaker in an energized 480-Volt (V) electrical panel.

409

Book Review: Arc Marine -GIS For A Blue Planet on 22-09-2007 10:44  

E-Print Network [OSTI]

and different types of sensors used to monitor and study oceans. The term marine in this book refers to deep commonly associated with ArcGIS. Unlike the shapefile, the geodatabase is much more robust in terms chapter, Search powered by About Contact Us Advertise Archives HOME NEWS ARTICLES DIALOGUE EVENTS V1 BLOGS

Wright, Dawn Jeannine

410

Experimental study of heat transfer in an electric arc gas heater with vortex stabilization of the discharge  

Science Journals Connector (OSTI)

The results of an experimental investigation into heat transfer in the discharge chamber of an electric-arc gas heater are presented. For the anode...an=f(I, d), St=f(l/d, Re, N/GH0). The energy losses in the bas...

V. L. Sergeev

1971-01-01T23:59:59.000Z

411

Time-dependence ion charge state distributions of vacuum arcs: An interpretation involving atoms and charge exchange collisions  

SciTech Connect (OSTI)

Experimentally observed charge state distributions are known to be higher at the beginning of each arc discharge. Up to know, this has been attributed to cathode surface effects in terms of changes of temperature, chemical composition and spot mode. Here it is shown that the initial decay of charge states of cathodic arc plasmas may at least in part due to charge exchange collisions of ions with neutrals that gradually fill the discharge volume. Sources of neutrals may include evaporated atoms from macroparticles and still-hot craters of previously active arc spots. More importantly, atoms are also produced by energetic condensation of the cathodic arc plasma. Self-sputtering is significant when ions impact with near-normal angle of incidence, and ions have low sticking probability when impacting at oblique angle of incidence. Estimates show that the characteristic time for filling the near-cathode discharge volume agrees well with the charge state decay time, and the likelihood of charge exchange is reasonably large to be taken into account.

Anders, Andre

2004-08-27T23:59:59.000Z

412

ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets  

E-Print Network [OSTI]

The affordable, robust, compact (ARC) reactor conceptual design study aims to reduce the size, cost, and complexity of a combined fusion nuclear science facility (FNSF) and demonstration fusion Pilot power plant. ARC is a 270 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has rare earth barium copper oxide (REBCO) superconducting toroidal field coils, which have joints to enable disassembly. This allows the vacuum vessel to be replaced quickly, mitigating first wall survivability concerns, and permits a single device to test many vacuum vessel designs and divertor materials. The design point has a plasma fusion gain of Q_p~13.6, yet is fully non-inductive, with a modest bootstrap fraction of only ~63%. Thus ARC offers a high power gain with relatively large external control of the current profile. This highly attractive combination is enabled by the ~23 T peak field on coil with newly available REBCO superconductor technology. External cu...

Sorbom, B N; Palmer, T R; Mangiarotti, F J; Sierchio, J M; Bonoli, P; Kasten, C; Sutherland, D A; Barnard, H S; Haakonsen, C B; Goh, J; Sung, C; Whyte, D G

2014-01-01T23:59:59.000Z

413

The Behaviour of Base Metals in Arc-Type Magmatic-Hydrothermal Systems Insights from Merapi Volcano,  

E-Print Network [OSTI]

zone stratovolcanoes provide important windows on the magmatic-hydrothermal processes at playThe Behaviour of Base Metals in Arc-Type Magmatic- Hydrothermal Systems ­ Insights from Merapi systems include a shallow magmatic reservoir (the porphyry stock), an overlying hydrothermal cell, its

Barnes, Sarah-Jane

414

The West Philippine Basin: An Eocene to early Oligocene back arc basin opened between two opposed subduction zones  

E-Print Network [OSTI]

counter-clockwise rotation of the spreading direction. The Gagua and Palau-Kyushu ridges acted as transform margins accommodating the opening. Arc volcanism occurred along the Palau-Kyushu Ridge (eastern behind the newly formed Palau-Kyushu Ridge, during a plate reorganization. This model was adopted

Demouchy, Sylvie

415

Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap  

SciTech Connect (OSTI)

A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent ''minimum-B'' structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 {mu}s) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

Nikolaev, A. G.; Savkin, K. P.; Oks, E. M.; Vizir, A. V.; Yushkov, G. Yu. [High Current Electronics Institute, Siberian Division of Russian Academy Science, Tomsk 634055 (Russian Federation); Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A. [Institute of Applied Physics, Russian Academy of Science, Nizhniy Novgorod 603950 (Russian Federation)

2012-02-15T23:59:59.000Z

416

2D Axisymmetric Coupled CFD-kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel  

E-Print Network [OSTI]

-assisted diesel fuel reformer developed for two different applications: (i) onboard H2 production for fuel cell been also developed for different reforming reactors: solid oxide fuel cell (SOFC)7 , membrane reformer1 2D Axisymmetric Coupled CFD-kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel

Boyer, Edmond

417

Explosive basaltic volcanism of the Chikurachki Volcano (Kurile arc, Russia): Insights on pre-eruptive magmatic conditions  

E-Print Network [OSTI]

Explosive basaltic volcanism of the Chikurachki Volcano (Kurile arc, Russia): Insights on pre-Sakhalinsk, Russia d Institute of Volcanic Geology and Geochemistry, 683006 Petropavlovsk-Kamchatsky, Russia e Vernadsky Institute of Geochemistry and Analytical Chemistry, 117975 Moscow, Russia Received 13 December

Belousov, Alexander

418

Cone-beam mammo-computed tomography from data along two tilting arcs Hengyong Yu,b  

E-Print Network [OSTI]

Cone-beam mammo-computed tomography from data along two tilting arcs Kai Zeng,a Hengyong Yu . To address this problem, x-ray tomosynthesis and cone-beam computed tomography CT are two compelling from a limited num- ber of projections.4 Since its introduction in 1972, the area of tomosynthesis has

Virginia Tech

419

All Other Edi~ims Arc Obolete United States Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

9-0s) 9-0s) All Other Edi~ims Arc Obolete United States Department of Energy E n e r g Finance and account in^ Sen'ice Center Travel Authorization and Program Manager Signature Card Name: Date: Position Title: Routing Symbol: BuiIding: Phone: Reporting EntityFund Code: Signature: Typcs of Documents Authorized (please check box) Approved Funding Program Change Request Procurement Authorization (PRs, direct chargebacks. etc.) Claim for Reimbursement for Espenditwre on Official Business (Local Travel) Travel Authorizations and Nodi fications Travel Vouchers Training Authorizations Training Invoice Payments Invoice Payment Approval Travel Authorizations and Modifications (actual expenses) Other (speci fyS - I certifL to the signature and authority of the above individual for the document noted.

420

TEAM HEV ARC HITECTURE ENGIN E FU EL TRANS MISSION EN ERGY STOR  

Broader source: Energy.gov (indexed) [DOE]

TEAM TEAM HEV ARC HITECTURE ENGIN E FU EL TRANS MISSION EN ERGY STOR AGE MO TOR Michigan Technological University Through-the-road Parallel 2.0-L 4 Cylinder Spark Ignition Reformulated Gasoline 4-speed Automatic COBASYS, Nickel Metal Hydride - 288V 50 kW Solectria AC Induction Transaxle Mississippi State University Through-the-road Parallel 1.9-L GM Direct Injection Turbo Diesel Bio Diesel (B20) GM F40 6-speed Manual Johnson Controls, Nickel Metal Hydride - 330V 45 kW Ballard Integrated Power Transaxle The Ohio State University Through-the-road Parallel 1.9-L GM Direct Injection Turbo Diesel Bio Diesel (B20) Aisin-Warner AF40 6-speed Automatic Transaxle Panasonic, Nickel Metal Hydride - 300V 67 kW Ballard AC Induction Transaxle /10.6 kW Kollmorgen Brushless DC Generator Pennsylvania State

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Spatial and time-dependent distribution of plasma parameters in the metal-halide arc lamp  

E-Print Network [OSTI]

It was shown by several authors that closed high pressure arc a.c. discharge in mercury vapors with addition of metal halide cannot be described in frames of the local thermodynamic equilibrium (LTE) model. However some plasma parameters (electron and high lying excited states densities as well as Hg metastable levels densities) are assumed to be in equilibrium with electron temperature and these assumptions are applied in plasma diagnostics. To verify these supposition the method of local plasma spectroscopy based on spatial and temporal distribution of spectral line profiles was developed. The experimental set up is based on diffraction spectrometer with large aperture, spatial scanning device and photodetector, which allows to carry out the measurements in chosen phases of current period. The software for data acquisition and processing is based on LabVIEW system. The original method of joint data processing was applied to data arrays containing spatial, spectral and temporal distribution of a source surfa...

Khakhaev, A; Ekimov, K; Soloviev, A; Khakhaev, Anatoly; Luizova, Lidia; Ekimov, Konstantin; Soloviev, Alexey

2004-01-01T23:59:59.000Z

422

Set up an Arc Welding Code with Enthalpy Method in Upwind Scheme  

SciTech Connect (OSTI)

In this study, a numerical code with enthalpy method in upwind scheme is proposed to estimate the distribution of thermal stress in the molten pool, which is primarily determined by the type of the input power and travel speed of heating source. To predict the cracker deficit inside the workpiece, a simulated program satisfying the diagonal domination and Scarborough criterion provides a stable iteration. Meantime, an experimental performance, operated by robot arm 'DR-400' to provide a steady and continuous arc welding, was also conducted to verify the simulated result. By surveying the consistence of molten pool bounded by contrast shade and simulated melting contour on the surface of workpiece, the validity of model proposed to predict the thermal cracker has been successfully identified.

Ho, J.-E. [Department of Mechanical Engineering, National Ilan University, Ilan, Taiwan (China)

2010-05-21T23:59:59.000Z

423

Model of the boundary layer of a vacuum-arc magnetic filter  

SciTech Connect (OSTI)

A model is developed to describe the electrostatic boundary layer in a positively biased magnetic filter in filtered arcs with low collisionality. The set of equations used includes the electron momentum equation, with an anomalous collision term due to micro-instabilities leading to Bohm diffusion, electron mass conservation, and Poisson equation. Analytical solutions are obtained, valid for the regimes of interest, leading to an explicit expression to determine the electron density current to the filter wall as a function of the potential of the filter and the ratio of electron density at the plasma to that at the filter wall. Using a set of planar and cylindrical probes it is verified experimentally that the mentioned ratio of electron densities remains reasonably constant for different magnetic field values and probe bias, which allows to obtain a closed expression for the current. Comparisons are made with the experimentally determined current collected at different sections of a positively biased straight filter.

Minotti, F.; Giuliani, L.; Grondona, D.; Della Torre, H.; Kelly, H. [Departamento de Fisica, FCEyN, Universidad de Buenos Aires, Instituto de Fisica del Plasma, CONICET-UBA, Cdad. Universitaria, Pab.I, 1428 Buenos Aires (Argentina)

2013-03-21T23:59:59.000Z

424

Photocatalysts of Cr Doped TiO2 Film Prepared by Micro Arc Oxidation  

Science Journals Connector (OSTI)

A series of Cr doped TiO2 films were prepared by micro arc oxidation (MAO) using an electrolyte of Na 3PO4+K2Cr2O7. X-ray diffraction and scanning electron microscopy revealed that the films mainly consisted of anatase phase with a porous surface morphology. The films have an excellent photocatalytic effect for degradation of methylene blue and decomposition of water under visible light illumination. This arises from the formation of Cr3+/Cr4+ and oxygen vacancy energy levels owing to Cr doping. The former reduces the electron-hole recombination chance while the latter generates a new gap between the conduction band (CB) and valence band (VB) of TiO2 which lowers the photo energy of the excited electron in the VB to the oxygen vacancy states. The mechanisms for film synthesis during the MAO process are also presented.

Li Wan; Jian-feng Li; Jia-you Feng; Wei Sun; Zong-qiang Mao

2008-01-01T23:59:59.000Z

425

Long-pulse arc-discharge plasma source with cold cathode for diagnostic neutral beam injector  

SciTech Connect (OSTI)

Long-pulse cold cathode arc-discharge plasma generators have been successfully used as high-quality hydrogen ion sources for plasma diagnostic neutral beams. One of the main advantages of this type of plasma source is a high proton fraction (80%-90%). However, the lifetime of the plasma source is limited due to intensive electrode's erosion, especially at the cathode region. An optimized design of the cathode and the nearest electrodes is found which reduces the erosion and allows us to increase the pulse length. The plasma source produces the extracted ion current up to 3 A at a low angular divergence, and at the pulse duration up to 2 s.

Deichuli, P. P.; Ivanov, A. A.; Stupishin, N. V. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

2008-02-15T23:59:59.000Z

426

The Luminosity of Mercury Vapor Distilled from the Arc in Vacuo.  

Science Journals Connector (OSTI)

Afterglow of Mercury Vapor from an Arc in Vacuum.—(1) The effect of an electric field on the spectrum was studied. It was found that charged grids decreased the luminosity without changing the color; but when, under certain conditions, the luminosity was increased, there was a change in the relative intensity of the lines. (2) The velocity of the vapor was measured by a stroboscopic method. The luminosity was decreased intermittently at a known frequency and the resulting "puffs" as they moved along the tube, were observed stroboscopically. From this velocity and the rate of distillation, the density of the vapor was computed. (3) Decay of luminosity along the tube was observed. (4) Theoretical discussion of these results leads to the conclusion that recombination of the positive and negative ions produced by the discharge, is the most probable cause of the afterglow.

Norman H. Ricker

1921-02-01T23:59:59.000Z

427

Three-dimensional Ion Distribution in a Filtered Vacuum Arc Discharge  

SciTech Connect (OSTI)

Three-dimensional measurements of the ion flux along the filter of a magnetically filtered d-c vacuum arc are presented. The device includes a metallic plasma-generating chamber with cooper electrodes coupled to a substrate chamber through a quarter-torus magnetic filter. The filtering magnetic field was high enough to magnetize the electrons but not the ions. The ion current distribution was studied using a multi-element Cu probes, placed at three different positions along the filter. The ion saturation current of each probe was measured by biasing the probe at -70V with respect the grounded anode. Preliminary results of the three dimensional ion flux distribution and the floating potential of the plasma as functions of the bias filter voltage and magnetic field intensity are reported.

Kelly, H.; Marquez, A.; Pirrera, M. [Instituto de Fisica del Plasma, CONICET-Dpto. de Fisica, FCEN, UBA, Ciudad Universitaria Pab. 1 (1428EHA) Ciudad de Buenos Aires (Argentina)

2006-12-04T23:59:59.000Z

428

Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65  

SciTech Connect (OSTI)

The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

Hashemi, S. H. [Department of Mechanical Engineering, University of Birjand, POBOX 97175-376, Birjand (Iran, Islamic Republic of); Mohammadyani, D. [Materials and Energy Research Center (MERC) POBOX 14155-4777, Tehran (Iran, Islamic Republic of)

2011-01-17T23:59:59.000Z

429

Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder Metallurgy Produced Titanium Alloys  

SciTech Connect (OSTI)

ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

Muth, Thomas R [ORNL; Yamamoto, Yukinori [ORNL; Frederick, David Alan [ORNL; Contescu, Cristian I [ORNL; Chen, Wei [ORNL; Lim, Yong Chae [ORNL; Peter, William H [ORNL; Feng, Zhili [ORNL

2013-01-01T23:59:59.000Z

430

High energy arcing fault fires in switchgear equipment : a literature review.  

SciTech Connect (OSTI)

In power generating plants, switchgear provide a means to isolate and de-energize specific electrical components and buses in order to clear downstream faults, perform routine maintenance, and replace necessary electrical equipment. These protective devices may be categorized by the insulating medium, such as air or oil, and are typically specified by voltage classes, i.e. low, medium, and high voltage. Given their high energy content, catastrophic failure of switchgear by means of a high energy arcing fault (HEAF) may occur. An incident such as this may lead to an explosion and fire within the switchgear, directly impact adjacent components, and possibly render dependent electrical equipment inoperable. Historically, HEAF events have been poorly documented and discussed in little detail. Recent incidents involving switchgear components at nuclear power plants, however, were scrupulously investigated. The phenomena itself is only understood on a very elementary level from preliminary experiments and theories; though many have argued that these early experiments were inaccurate due to primitive instrumentation or poorly justified methodologies and thus require re-evaluation. Within the past two decades, however, there has been a resurgence of research that analyzes previous work and modern technology. Developing a greater understanding of the HEAF phenomena, in particular the affects on switchgear equipment and other associated switching components, would allow power generating industries to minimize and possibly prevent future occurrences, thereby reducing costs associated with repair and downtime. This report presents the findings of a literature review focused on arc fault studies for electrical switching equipment. The specific objective of this review was to assess the availability of the types of information needed to support development of improved treatment methods in fire Probabilistic Risk Assessment (PRA) for nuclear power plant applications.

Nowlen, Steven Patrick; Brown, Jason W.; Wyant, Francis John

2008-10-01T23:59:59.000Z

431

Canyon and channel networks of Peru-Chile fore arc at Arica Bight  

SciTech Connect (OSTI)

Canyons and channels of the Peru-Chile fore arc between 17{degree}30'S to 19{degree}30'S form a complex, integrated network revealed in SeaMARC II side-scan mosaics. The largest canyon, incised 200-600 m, is bordered by a series of sidewall slumps, producing a sinuosity that mimics subaerial meanders. The canyon courses across the Arequipa fore-arc basin floor, across a structural high and onto the middle trench slope to about 4,000 m where it disappears into a background of complex small-scale structures, From 500-2,500 m depth the canyon strikes north-south oblique to the regional slope. At 2,500 m, it abruptly turns to the southwest toward the trench axis. At this elbow, a second canyon heads on the midslope and also trends north-south until 3,500 m, where it too abruptly changes to a southwest course. A history of stream piracy analogous to subaerial systems is implied in this geometry. Tributaries join this main canyon from the landward side, forming a dendritic pattern. These channels have levees which are linked by submarine crevasse splays to sediment waves on the Arequipa basin floor. The orientation of the waves is reminiscent of bow waves from a passing ship, oblique to channel and pointing downslope, and may provide an indication of the vertical extent of passing turbidity currents. Sediments are dominantly olive gray, hemipelagic silts with sands present only immediately adjacent to the canyons. Boulders of mudstone line portions of the canyon floor. Sands are absent from the lowermost slope and trench axis, as are any indications of submarine fans. Sands may be rare in this system, with those that are present kneaded into the active margin system along the lower trench slope.

Coulbourn, W.T. (Hawaii Institute of Geophysics, Honolulu (USA))

1990-05-01T23:59:59.000Z

432

Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace  

SciTech Connect (OSTI)

This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electric arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.

Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

2014-01-01T23:59:59.000Z

433

Symbolic dynamics  

E-Print Network [OSTI]

This chapter presents some of the links between automata theory and symbolic dynamics. The emphasis is on two particular points. The first one is the interplay between some particular classes of automata, such as local automata and results on embeddings of shifts of finite type. The second one is the connection between syntactic semigroups and the classification of sofic shifts up to conjugacy.

Béal, M -P; Eilers, S; Perrin, D

2010-01-01T23:59:59.000Z

434

Development and clinical evaluation of automatic fiducial detection for tumor tracking in cine megavoltage images during volumetric modulated arc therapy  

SciTech Connect (OSTI)

Purpose: Real-time tracking of implanted fiducials in cine megavoltage (MV) imaging during volumetric modulated arc therapy (VMAT) delivery is complicated due to the inherent low contrast of MV images and potential blockage of dynamic leaves configurations. The purpose of this work is to develop a clinically practical autodetection algorithm for motion management during VMAT. Methods: The expected field-specific segments and the planned fiducial position from the Eclipse (Varian Medical Systems, Palo Alto, CA) treatment planning system were projected onto the MV images. The fiducials were enhanced by applying a Laplacian of Gaussian filter in the spatial domain for each image, with a blob-shaped object as the impulse response. The search of implanted fiducials was then performed on a region of interest centered on the projection of the fiducial when it was within an open field including the case when it was close to the field edge or partially occluded by the leaves. A universal template formula was proposed for template matching and normalized cross correlation was employed for its simplicity and computational efficiency. The search region for every image was adaptively updated through a prediction model that employed the 3D position of the fiducial estimated from the localized positions in previous images. This prediction model allowed the actual fiducial position to be tracked dynamically and was used to initialize the search region. The artifacts caused by electronic interference during the acquisition were effectively removed. A score map was computed by combining both morphological information and image intensity. The pixel location with the highest score was selected as the detected fiducial position. The sets of cine MV images taken during treatment were analyzed with in-house developed software written in MATLAB (The Mathworks, Inc., Natick, MA). Five prostate patients were analyzed to assess the algorithm performance by measuring their positioning accuracy during treatment. Results: The algorithm was able to accurately localize the fiducial position on MV images with success rates of more than 90% per case. The percentage of images in which each fiducial was localized in the studied cases varied between 23% and 65%, with at least one fiducial having been localized between 40% and 95% of the images. This depended mainly on the modulation of the plan and fiducial blockage. The prostate movement in the presented cases varied between 0.8 and 3.5 mm (mean values). The maximum displacement detected among all patients was of 5.7 mm. Conclusions: An algorithm for automatic detection of fiducial markers in cine MV images has been developed and tested with five clinical cases. Despite the challenges posed by complex beam aperture shapes, fiducial localization close to the field edge, partial occlusion of fiducials, fast leaf and gantry movement, and inherently low MV image quality, good localization results were achieved in patient images. This work provides a technique for enabling real-time accurate fiducial detection and tumor tracking during VMAT treatments without the use of extra imaging dose.

Azcona, Juan Diego [Department of Radiation Oncology, Stanford University, Stanford, California 94305 and Department of Oncology, Division of Radiation Physics, Clinica Universidad de Navarra, Pamplona, Navarra 31008 (Spain); Li Ruijiang; Mok, Edward; Hancock, Steven; Xing Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

2013-03-15T23:59:59.000Z

435

Effect of temperature and arc discharge on friction and wear behaviours of carbon strip/copper contact wire in pantograph–catenary systems  

Science Journals Connector (OSTI)

A series of tests on friction and wear performance of pure copper rubbing against carbon strip under electric current have been carried out on a modified pin-on-disc friction and wear tester. The results indicate that there are temperature rise and arc discharge in the electrical sliding processes. The temperature rise of contact pairs and the intensity of arc discharge increase with the increasing of electric current. However, the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. The increase in wear volume of the carbon strip is mainly caused by high temperature of contact pairs and arc discharge phenomenon. The test results also show that the wear volume of pin specimen with arc discharge is much greater than that without arc discharge under the same temperature. Therefore, the thermal wear due to high temperature has a distinct influence on the service life of pantograph contact strip and arc erosion even has more significant influence. Cooling measures should be applied in pantograph/catenary systems. Especially, off-line arc discharge of the contact couple should be suppressed to the maximum extent to extend the service life of pantograph contact strip.

T. Ding; G.X. Chen; J. Bu; W.H. Zhang

2011-01-01T23:59:59.000Z

436

Comparative study of two- and three-dimensional modeling on arc discharge phenomena inside a thermal plasma torch with hollow electrodes  

SciTech Connect (OSTI)

A comparative study between two- and three-dimensional (2D and 3D) modeling is carried out on arc discharge phenomena inside a thermal plasma torch with hollow electrodes, in order to evaluate the effects of arc root configuration characterized by either 2D annular or 3D highly localized attachment on the electrode surface. For this purpose, a more precise 3D transient model has been developed by taking account of 3D arc current distribution and arc root rotation. The 3D simulation results apparently reveal that the 3D arc root attachment brings about the inherent 3D and turbulence nature of plasma fields inside the torch. It is also found that the constricted arc column near the vortex chamber plays an important role in heating and acceleration of injected arc gases by concentrating arc currents on the axis of the hollow electrodes. The inherent 3D nature of arc discharge is well preserved inside the cathode region, while these 3D features slowly diminish behind the vortex chamber where the turbulent flow begins to be developed in the anode region. Based on the present simulation results, it is noted that the mixing effects of the strong turbulent flow on the heat and mass transfer are mainly responsible for the gradual relaxation of the 3D structures of plasma fields into the 2D axisymmetric ones that eventually appear in the anode region near the torch exit. From a detailed comparison of the 3D results with the 2D ones, the arc root configuration seems to have a significant effect on the heat transfer to the electrode surfaces interacting with the turbulent plasma flow. That is, in the 2D simulation based on an axisymmetric stationary model, the turbulence phenomena are fairly underestimated and the amount of heat transferred to the cold anode wall is calculated to be smaller than that obtained in the 3D simulation. For the validation of the numerical simulations, calculated plasma temperatures and axial velocities are compared with experimentally measured ones, and the 3D simulation turns out to be more accurate than the 2D simulation as a result of a relatively precise description of the turbulent phenomena inside the torch using a more realistic model of arc root attachment. Finally, it is suggested that the 3D transient formulation is indeed required for describing the real arc discharge phenomena inside the torch, while the 2D stationary approach is sometimes useful for getting practical information about the time-averaged plasma characteristics outside the torch because of its simplicity and rapidness in computation.

Kim, Keun Su; Park, Jin Myung; Choi, Sooseok; Kim, Jongin; Hong, Sang Hee [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2008-02-15T23:59:59.000Z

437

Introduction Dynamic Risk Measures  

E-Print Network [OSTI]

Introduction Dynamic Risk Measures Dynamic Risk Measures from BMO martingales Bid-Ask Dynamic Pricing Procedure Conclusion MESURES DE RISQUE DYNAMIQUES DYNAMIC RISK MEASURES Jocelyne Bion-Nadal CNRS Risk Measures Dynamic Risk Measures from BMO martingales Bid-Ask Dynamic Pricing Procedure Conclusion

Bion-Nadal, Jocelyne

438

Detection and correction for EPID and gantry sag during arc delivery using cine EPID imaging  

SciTech Connect (OSTI)

Purpose: Electronic portal imaging devices (EPIDs) have been studied and used for pretreatment and in-vivo dosimetry applications for many years. The application of EPIDs for dosimetry in arc treatments requires accurate characterization of the mechanical sag of the EPID and gantry during rotation. Several studies have investigated the effects of gravity on the sag of these systems but each have limitations. In this study, an easy experiment setup and accurate algorithm have been introduced to characterize and correct for the effect of EPID and gantry sag during arc delivery. Methods: Three metallic ball bearings were used as markers in the beam: two of them fixed to the gantry head and the third positioned at the isocenter. EPID images were acquired during a 360 deg. gantry rotation in cine imaging mode. The markers were tracked in EPID images and a robust in-house developed MATLAB code was used to analyse the images and find the EPID sag in three directions as well as the EPID + gantry sag by comparison to the reference gantry zero image. The algorithm results were then tested against independent methods. The method was applied to compare the effect in clockwise and counter clockwise gantry rotations and different source-to-detector distances (SDDs). The results were monitored for one linear accelerator over a course of 15 months and six other linear-accelerators from two treatment centers were also investigated using this method. The generalized shift patterns were derived from the data and used in an image registration algorithm to correct for the effect of the mechanical sag in the system. The Gamma evaluation (3%, 3 mm) technique was used to investigate the improvement in alignment of cine EPID images of a fixed field, by comparing both individual images and the sum of images in a series with the reference gantry zero image. Results: The mechanical sag during gantry rotation was dependent on the gantry angle and was larger in the in-plane direction, although the patterns were not identical for various linear-accelerators. The reproducibility of measurements was within 0.2 mm over a period of 15 months. The direction of gantry rotation and SDD did not affect the results by more than 0.3 mm. Results of independent tests agreed with the algorithm within the accuracy of the measurement tools. When comparing summed images, the percentage of points with Gamma index <1 increased from 85.4% to 94.1% after correcting for the EPID sag, and to 99.3% after correction for gantry + EPID sag. Conclusions: The measurement method and algorithms introduced in this study use cine-images, are highly accurate, simple, fast, and reproducible. It tests all gantry angles and provides a suitable automatic analysis and correction tool to improve EPID dosimetry and perform comprehensive linac QA for arc treatments.

Rowshanfarzad, Pejman; Sabet, Mahsheed; O'Connor, Daryl J.; McCowan, Peter M.; McCurdy, Boyd M. C.; Greer, Peter B. [School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW 2308 (Australia); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 (Canada) and Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physics and Astronomy, University of Manitoba,Winnipeg, Manitoba R3T 2N2 (Canada) and Department of Radiology, University of Manitoba, Winnipeg, Manitoba R3A 1R9 (Canada); Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Newcastle, NSW 2310 (Australia) and School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW 2308 (Australia)

2012-02-15T23:59:59.000Z

439

The Molecular Structure of a Phosphatidylserine Bilayer Determined by Scattering and Molecular Dynamics Simulations  

SciTech Connect (OSTI)

Phosphatidylserine (PS) lipids play essential roles in biological processes, including enzyme activation and apoptosis. We report on the molecular structure and atomic scale interactions of a fluid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS). A scattering density profile model, aided by molecular dynamics (MD) simulations, was developed to jointly refine different contrast small-angle neutron and X-ray scattering data, which yielded a lipid area of 62.7 A2 at 25 C. MD simulations with POPS lipid area constrained at different values were also performed using all-atom and aliphatic united-atom models. The optimal simulated bilayer was obtained using a model-free comparison approach. Examination of the simulated bilayer, which agrees best with the experimental scattering data, reveals a preferential interaction between Na+ ions and the terminal serine and phosphate moieties. Long-range inter-lipid interactions were identified, primarily between the positively charged ammonium, and the negatively charged carboxylic and phosphate oxygens. The area compressibility modulus KA of the POPS bilayer was derived by quantifying lipid area as a function of surface tension from area-constrained MD simulations. It was found that POPS bilayers possess a much larger KA than that of neutral phosphatidylcholine lipid bilayers. We propose that the unique molecular features of POPS bilayers may play an important role in certain physiological functions.

Pan, Jianjun [University of South Florida, Tampa (USF)] [University of South Florida, Tampa (USF); Cheng, Xiaolin [ORNL] [ORNL; Monticelli, Luca [Institut National de la Santé et de la Recherche Médicale (INSERM) and INTS, France] [Institut National de la Santé et de la Recherche Médicale (INSERM) and INTS, France; Heberle, Frederick A [ORNL] [ORNL; Kucerka, Norbert [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,] [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,; Tieleman, D. Peter [University of Calgary, ALberta, Canada] [University of Calgary, ALberta, Canada; Katsaras, John [ORNL] [ORNL

2014-01-01T23:59:59.000Z

440

Recent Advances in Atomic-Scale Spin-Polarized Scanning Tunneling Microscopy  

E-Print Network [OSTI]

, Faradayweg 4-6 D-14195 Berlin (Dahlem) Germany WALTER R. L. LAMBRECHT Department of Physics, Case Western of atomically clean magnetic surfaces. Several key findings have been obtained. First, both magnetic and non Nanometer scale science and technology has been an area of intense research and development activity within

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

E-Print Network 3.0 - atomic scale interface Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Grain Boundaries: LBNL and ORNL Key Insights... a range of rare-earth atoms in sintering additives bond to the interface between the intergranular phase... to the interface at a...

442

E-Print Network 3.0 - atomic scale magnetometry Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics 7 nature physics | VOL 3 | APRIL 2007 | www.nature.comnaturephysics 227 REVIEW ARTICLE Summary: ,8. The fields of resonant magneto-optics and atomic magnetometry...

443

Nanotechnology Nanotechnology comprises measurement, design, modeling and fabrication of materials and systems at the atomic scale.  

E-Print Network [OSTI]

Nanotechnology Nanotechnology comprises measurement, design, modeling and fabrication of materials are able to customize their education by specializing in areas such as nanotechnology, computational

Glowinski, Roland

444

E-Print Network 3.0 - atomic scale defect Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

assembled DNA nanostructures. Atomic force microscope (AFM) images are used... of defect identification. 4.1 Defect ... Source: Chakrabarty, Krishnendu - Department of Electrical...

445

Atomic scale studies of interface formation between oxides and III-V semiconductor surfaces  

E-Print Network [OSTI]

112 Figure 35. Reaction of IPA with InAs(0 0 1)-(4 × 2) vs.116 Figure 36. IPA dosing at 25 °C and annealing at 200 °C,121 vii STS measurements for IPA, H 2 O, HOOH on n- and p-

Clemens, Jonathon Boyd

2010-01-01T23:59:59.000Z

446

E-Print Network 3.0 - atomic scale study Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Theory group in the Atomic Physics division, Department of Physics... - Resonances- in Atoms and Ions Recombination processes in electron-ion collisions - Dielectronic...

447

E-Print Network 3.0 - atomic scale images Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in the scattering of light by a condensate Summary: , and atoms at 45 degrees. (b-g) Absorption images after 20 ms time-of-flight show the atomic momentum... appears to be...

448

Atomic scale studies of interface formation between oxides and III-V semiconductor surfaces  

E-Print Network [OSTI]

King, CRC Handbook of Chemistry and Physics, 89th Edition,Luo, CRC Handbook of Chemistry and Physics, 89th Edition,in CRC Handbook of Chemistry and Physics, 90th edition (

Clemens, Jonathon Boyd

2010-01-01T23:59:59.000Z

449

Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory  

Science Journals Connector (OSTI)

...energy efficiency, gas turbine engines used in...designing circumvention strategies. We review results...energy: Both employ turbine engines that combust...more expansion of gas that creates more...for most materials development, the usual path...

Kristen A. Marino; Berit Hinnemann; Emily A. Carter

2011-01-01T23:59:59.000Z

450

On the thermodynamic efficiency of a multiferroic thermomagnetic generator: From bulk to atomic scale  

E-Print Network [OSTI]

K. P. & Carman, G. P. “Energy conversion efficiency analysisand Gregory P Carman. “Energy conversion efficiency analysis19th Intersociety Energy Conversion Engineering Conference (

Sandoval, Samuel M.

2014-01-01T23:59:59.000Z

451

On the thermodynamic efficiency of a multiferroic thermomagnetic generator: From bulk to atomic scale  

E-Print Network [OSTI]

inductor for electrical energy harvesting. . . . . . . . . .magnetic inductor for electrical energy harvesting, compareand produce useful electrical energy and they all appear to

Sandoval, Samuel M.

2014-01-01T23:59:59.000Z

452

On the thermodynamic efficiency of a multiferroic thermomagnetic generator: From bulk to atomic scale  

E-Print Network [OSTI]

of the first-law of thermodynamics must be satisfiedFurthermore, the second-law of thermodynamics establishes anterm until the first-law of thermodynamics is applied to the

Sandoval, Samuel M.

2014-01-01T23:59:59.000Z

453

Atomic scale studies of interface formation between oxides and III-V semiconductor surfaces  

E-Print Network [OSTI]

Kelvin probe microscopy in UHV conditions is an exception.TMA trimethyl aluminum UHV ultra high vacuum VASP Vienna abthe tools necessary for my UHV chamber to produce the data

Clemens, Jonathon Boyd

2010-01-01T23:59:59.000Z

454

Probing Atomic-Scale Properties of Organic and Organometallic Molecules by Scanning Tunneling Spectroscopy  

E-Print Network [OSTI]

LUMO ML NDR NRG rms RT STM STS UHV Density Functional Theorybuilt ultra-high vacuum (UHV) STM. The base pressure is ? 1An overview of the cryogenic UHV STM is shown in figure 5.1.

Yamachika, Ryan

2009-01-01T23:59:59.000Z

455

X-ray Laser Used to Produce Movies of Atomic-scale Motion | U...  

Office of Science (SC) Website

with open access in the Supplementary Information External link at the publication web site. Highlight Categories Program: BES, MSE, SUF PerformerFacility: DOE Laboratory,...

456

E-Print Network 3.0 - atomic scale characterization Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to Materials Properties: Using ... Source: Heller, Barbara - Department of Applied Mathematics, Illinois Institute of Technology Collection: Mathematics 2 Master...

457

Atomic-scale characterization of germanium isotopic multilayers by atom probe tomography  

SciTech Connect (OSTI)

We report comparison of the interfacial sharpness characterization of germanium (Ge) isotopic multilayers between laser-assisted atom probe tomography (APT) and secondary ion mass spectrometry (SIMS). An alternating stack of 8-nm-thick naturally available Ge layers and 8-nm-thick isotopically enriched {sup 70}Ge layers was prepared on a Ge(100) substrate by molecular beam epitaxy. The APT mass spectra consist of clearly resolved peaks of five stable Ge isotopes ({sup 70}Ge, {sup 72}Ge, {sup 73}Ge, {sup 74}Ge, and {sup 76}Ge). The degree of intermixing at the interfaces between adjacent layers was determined by APT to be around 0.8 {+-} 0.1 nm which was much sharper than that obtained by SIMS.

Shimizu, Y.; Takamizawa, H.; Toyama, T.; Inoue, K.; Nagai, Y. [Oarai Center, Institute for Materials Research, Tohoku University, 2145-2 Narita, Oarai, Ibaraki 311-1313 (Japan); Kawamura, Y.; Uematsu, M.; Itoh, K. M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Haller, E. E. [University of California at Berkeley and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

2013-01-14T23:59:59.000Z

458

Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory  

Science Journals Connector (OSTI)

...coatings for gas-turbine engine applications...Materials Science and Technology—A Comprehensive Treatment...for industrial gas turbines . P I Mech Eng...Singheiser L ( 1999 ) Development of NiCrAlY alloys...barrier coatings of gas turbine components...

Kristen A. Marino; Berit Hinnemann; Emily A. Carter

2011-01-01T23:59:59.000Z

459

Dynamic Positioning Simulator Dynamic Positioning Simulator  

E-Print Network [OSTI]

Simulator 5 / 24 #12;Dynamic Positioning Simulator Dynamic Positioning Why Dynamic Positioning? Advantages Dynamic Positioning: No tugboats needed; Offshore set-up is quick; Power saving; Precision situations more on Ship: Wind Force Fw = 1 2 air V 2 rw CXw (rw )AT 1 2 air V 2 rw CYw (rw )AL Mw = 1 2 air V 2 rw CMw (rw

Vuik, Kees

460

Web: http://dust.ess.uci.edu/prp/prp_ans/prp_ans.pdf NSF Arctic Natural Sciences (ANS) Proposal ARC-0714088 Submitted: December 8, 2006  

E-Print Network [OSTI]

Web: http://dust.ess.uci.edu/prp/prp_ans/prp_ans.pdf NSF Arctic Natural Sciences (ANS) Proposal ARC dissemination of LGGE snow measurements as http://dust.ess.uci.edu/snw. Identified IPY sub-disciplines as Snow

Zender, Charles

Note: This page contains sample records for the topic "arcs atomic-scale dynamics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Product/metal ratio (PMR): A novel criterion for the evaluation of electrolytes on micro-arc oxidation (MAO) of Mg and its alloys  

Science Journals Connector (OSTI)

Product/metal ratio (PMR...) was introduced as a novel criterion for the evaluation of electrolytes on micro-arc oxidation (MAO) of Mg and its alloys....PBR), focused on the roles of electrolytes for the compactn...

LaiWen Song; YingWei Song; DaYong Shan; GuoYi Zhu…

2011-10-01T23:59:59.000Z

462

Improvement in corrosion resistance of micro arc oxidation coating formed on AZ91D magnesium alloy via applying a nano-crystalline sol–gel layer  

Science Journals Connector (OSTI)

Although magnesium is used in many industries, it is reactive and requires protection against aggressive environments. In this study, oxide coating was formed on AZ91D magnesium alloy using micro-arc oxidation (M...

M. Laleh; Farzad Kargar; A. Sabour Rouhaghdam

2011-08-01T23:59:59.000Z

463

A Study on the Deposition of Al2O3 Coatings on Polymer Substrates by a Plasma Spray/Micro-Arc Oxidation Two-Step Method  

Science Journals Connector (OSTI)

To increase the wear resistance of polymer matrix composites, alumina coatings were deposited on polymer substrates by a two-step method combining plasma spraying and micro-arc oxidation. The microstructures and ...

Guanhong Sun; Xiaodong He; Jiuxing Jiang; Yue Sun…

2013-02-01T23:59:59.000Z

464

Improved tribo-mechanical behavior of CaP-containing TiO2 layers produced on titanium by shot blasting and micro-arc oxidation  

Science Journals Connector (OSTI)

The combination of shot blasting (SB) and micro-arc oxidation (or anodic oxidation—AO) in titanium surfaces was shown to...2 layers were produced on AO and SB + AO. The latter presented small pore size and inhomo...

Eduardo M. Szesz; Gelson B. de Souza…

2014-10-01T23:59:59.000Z

465

Fretting Wear Study on Micro-Arc Oxidation TiO2 Coating on TC4 Titanium Alloys in Simulated Body Fluid  

Science Journals Connector (OSTI)

Tribological properties of TiO2 coatings synthesized by micro-arc oxidation (MAO) on the surface of TC4...2 coatings presented good tribological properties with lower friction coefficient in SBF. Less wear volume...

Guanghong Zhou; Hongyan Ding; Yue Zhang; Aihui Liu; Yuebin Lin…

2010-12-01T23:59:59.000Z

466

A study of the physical, chemical and biological properties of TiO2 coatings produced by micro-arc oxidation in a Ca–P-based electrolyte  

Science Journals Connector (OSTI)

In this work, a porous and homogeneous titanium dioxide layer was grown on commercially pure titanium substrate using a micro-arc oxidation (MAO) process and Ca–P-based...2 coatings were characterized by X-ray di...

Amanda dos Santos; Joyce R. Araujo…

2014-07-01T23:59:59.000Z

467

Single phase synthesis of ?-brass (Cu5Zn8) nanoparticles by electric arc discharge method and investigation of their order–disorder transition temperature  

Science Journals Connector (OSTI)

Abstract Single phase ?-brass (Cu5Zn8) nanoparticles were synthesized using the electric arc discharge method. The effect of various arc currents and pressures on the size and phase purity of the Cu–Zn alloy was studied. The arc currents of 200, 300 and 400 A and chamber pressures of 1, 2 and 3 atm of Ar were examined. The samples were characterized using XRD and SEM measurements. The results showed that the spherical nanoparticles of Cu5Zn8 with a mean particle size of 21 nm were produced at a pressure of 1 atm and an arc current of 300 A. Post annealing and quenching of the samples were used to investigate the order disorder phase transformation temperature of Cu5Zn8 in the nanosized form. The XRD analyses showed that the disorder phase starts at 400 °C and completes at 480 °C which is different from the bulk brasses.

Mansoor Farbod; Alireza Mohammadian

2014-01-01T23:59:59.000Z

468

On the structure and properties of a material deposited from arc discharge plasma near the cathode and onto vacuum-chamber walls  

Science Journals Connector (OSTI)

The structure and composition of a material (composite) deposited onto vacuum-chamber walls from arc discharge plasma during the crystallization of cathode spot products in electric and magnetic fields is studied...

N. A. Smolanov; N. A. Pankin

2014-09-01T23:59:59.000Z

469

Bend-insensitive ultra short long-period gratings by the electric arc method and their applications to harsh environment sensing and communication  

Science Journals Connector (OSTI)

Ultra short long-period gratings (LPGs) fabricated using the electric arc discharge method are demonstrated with regular single-mode fibers. The gratings were as short as two...

Nam, Sung; Zhan, Chun; Lee, Jon; Hahn, Corey; Reichard, Karl; Ruffin, Paul; Deng, Kung-Li; Yin, Shizhuo

2005-01-01T23:59:59.000Z

470

Gyrocenter Shift of Low-Temperature Plasmas and the Retrograde Motion of Cathode Spots in Arc Discharges  

SciTech Connect (OSTI)

The gyrocenter shift phenomenon explained the mechanism of radial electric field formation at the high confinement mode transition in fusion devices. This Letter reports that the theory of gyrocenter shift is also applicable to low temperature high collisional plasmas such as arc discharges by the generalization of the theory resulting from a short mean free path compared with the gyroradius. The retrograde motion of cathode spots in the arc discharge is investigated through a model with the expanded formula of gyrocenter shift. It is found that a reversed electric field is formed in front of the cathode spots when they are under a magnetic field, and this reversed electric field generates a rotation of cathode spots opposite to the Amperian direction. The ion drift velocity profiles calculated from the model are in agreement with the experimental results as functions of magnetic flux density and gas pressure.

Lee, K. C. [Department of Applied Science, University of California, Davis, California 95616 (United States)

2007-08-10T23:59:59.000Z

471

High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc  

SciTech Connect (OSTI)

Metal ions were extracted from pulsed discharge plasmas operating in the transition region between vacuum spark (transient high voltage of kV) and vacuum arc (arc voltage ~;; 20 V). At a peak current of about 4 kA, and with a pulse duration of 8 ?s, we observed mean ion charges states of about 6 for several cathode materials. In the case of platinum, the highest average charge state was 6.74 with ions of charge states as high as 10 present. For gold we found traces of charge state 11, with the highest average charge state of 7.25. At currents higher than 5 kA, non-metallic contaminations started to dominate the ion beam, preventing further enhancement of the metal charge states.

Yushkov, Georgy Yu.; Anders, A.

2008-06-19T23:59:59.000Z

472

Electronic Structure and Field Emission Properties of Double-Walled Carbon Nanotubes Synthesized by Hydrogen Arc Discharge  

Science Journals Connector (OSTI)

Electronic Structure and Field Emission Properties of Double-Walled Carbon Nanotubes Synthesized by Hydrogen Arc Discharge ... 36-38 By the way, as shown in Figure 6a, the current density of DWCNTs shows much lower level than that of SWCNTs in a low electric field region below 4 V/?m, but it reaches a slightly higher level in a medium electric field region of 4?6 V/?m. ...

Byeongchul Ha; Dong Hoon Shin; Jeunghee Park; Cheol Jin Lee

2007-12-22T23:59:59.000Z

473

Alteration of volcaniclastic debris and basalts in a submarine remnant arc: deep sea drilling project site 448, Palau-Kyushu Ridge, Philippine Sea  

E-Print Network [OSTI]

of i. terstial water, (c) ". ates and depths of burial, (d) geothermal and pressure gradiencs, (e) interstitial fluid flow rates, and (f) tectonic stresses. There have been few complete studies made on the mineralogical and chemical alteration... (Karig, 1975b; Scott, et al. , 1981). Presumably the thermal alteration process that affected the arc during the initial stages of arc formation must have died out soon after the cessation of volcanism. Hopefuliy a lowering of geothermal gradients...

Aldrich, Jeffrey Brooks

2012-06-07T23:59:59.000Z

474

Synthesis Gas Production by Combined Reforming of CO2-Containing Natural Gas with Steam and Partial Oxidation in a Multistage Gliding Arc Discharge System  

Science Journals Connector (OSTI)

Synthesis Gas Production by Combined Reforming of CO2-Containing Natural Gas with Steam and Partial Oxidation in a Multistage Gliding Arc Discharge System ... with low-current arcs available in the literature. ... Larkin, D. W.; Caldwell, T. A.; Lobban, L. L.; Mallinson, R. G.Oxygen pathways and carbon dioxide utilization in methane partial oxidation in ambient temperature electric discharges Energy Fuels 1998, 12, 740 ...

Krittiya Pornmai; Narissara Arthiwet; Nongnuch Rueangjitt; Hidetoshi Sekiguchi; Sumaeth Chavadej

2014-07-08T23:59:59.000Z

475

Optimization of Weld Bead Penetration in Pulsed Gas Metal Arc Welding using Genetic Algorithm  

E-Print Network [OSTI]

Abstract — The weld quality is highly influenced by various process parameters involved in the process. This can be achieved by meeting quality requirements of bead geometry. Inadequate depth of penetration will contribute to failure of the welded structure. This paper presents the development of genetic algorithm model for the optimization of depth of penetration of weld bead geometry in pulsed gas metal arc welding process. The model is based on experimental data. The thickness of the plate, pulse frequency, wire feed rate, wire feed rate/travel speed ratio, and peak current have been considered as the process parameters to maximize the bead penetration depth. Optimization of process parameters was done using GA. The developed model is then compared with experimental results and it is found that the results obtained from genetic algorithm model are accurate. The optimal process parameters gave a value of 5.314 for depth of penetration which demonstrates an accuracy of 1.33 % and thus the effectiveness of the model presented. The obtained results help in selecting quickly the process parameters to achieve the desired quality. Keywords—Genetic algorithm, Pulsed GMA welding, Welding parameters, Depth of penetration, Regression mode I.

K. Manikya Kanti; P. Srinivasa Rao; G. Ranga Janardhana

476

Hydrothermal circulation in an anisotropic sedimentary basin: Application to the Okinawa back arc basin  

SciTech Connect (OSTI)

The authors explore the pattern of two-dimensional convection in an highly anisotropical porous medium. This physical situation is relevant to passive margin sedimentary basins consisting of interbedded coarse-grained pervious and shale matrix. They show that permeability anisotropies of the order of 10{sup 2}-10{sup 4} allow for long convective cells, of aspect ratio greater than 10, but that a combination of this parameter with a slight slope of the order of a few percent of the sedimentary layers is required to stabilize these long cells. As an example, they present the Okinawa basin, an active submarine back arc basin, with a sedimentary thickness of about 2 km and a heat flow profile across this basin, varying from 32 to 232 mWm{sup {minus}2} over a distance of 30 km. It is shown that this heat flow variation is difficult to explain with conductive mechanisms only but is well reproduced by different convective models relying on permeability anisotropy plus slope. Although the insufficient thermal and structural constraints did not allow them to build a unique model, the whole set of possible fits to the heat flow data may restrict the mean hydraulic parameters of the basin. A vertical permeability of a few tens of milidarcy and an anisotropy greater than 100 are required to produce the expected stable and active large-scale circulation. It is suggested in conclusion that this type of circulation might be active in oil- or oil-forming element migration.

Genthon, P.; Rabinowicz, M. (Groupe de Recherches de Geodesie, Spatiale (France)); Foucher, J.P.; Sibuet, J.C. (Inst. Francais de Recherches pour l'Exploitation de la Mer, Plouzane (France))

1990-11-10T23:59:59.000Z

477

Establishing an optimized patient-specific verification program for volumetric modulated arc therapy  

SciTech Connect (OSTI)

Quality assurance (QA) of volumetric modulated arc therapy (VMAT) increases the workload significantly. We compared the results from 4 verification methods to establish an efficient VMAT QA. Planning for VMAT treatments was carried out for 40 consecutive patients. Pretreatment verifications were carried out with ion chamber array Physikalish-Technische Werkstätten (PTW729), electronic portal dosimetry (EPID), ion chamber measurements, and independent dose calculation with Diamond program. 2D analyses were made using the gamma analysis (3 mm distance to agreement and 3% dose difference relative to maximum, 10% dose threshold). Average point dose difference calculated by Eclipse relative to ion chamber measurements and Diamond were 0.1%±0.9% and 0.6%±2.2%, respectively. Average pass rate for PTW729 was 99.2%±1.9% and 98.3%±1.3% for EPID. The total required time (linac occupancy time given in parentheses) for each QA method was: PTW729 43.5 minutes (26.5 minutes), EPID 14.5 minutes (2.5 minutes), ion chamber 34.5 minutes (26.5 minutes), and Diamond 12.0 minutes (0 minute). The results were consistent and allowed us to establish an optimized protocol, considering safety and accuracy as well as workload, consisting of 2 verification methods: EPID 2D analysis and independent dose calculation.

Serna, Alfredo, E-mail: alfredo.serna@carm.es [Department of Medical Physics, Hospital Universitario Santa Lucía, Cartagena (Spain); Mata, Fernando; Puchades, Vicente [Department of Medical Physics, Hospital Universitario Santa Lucía, Cartagena (Spain)

2013-10-01T23:59:59.000Z

478

LARGE AREA FILTERED ARC DEPOSITION OF CARBON AND BORON BASED HARD COATINGS  

SciTech Connect (OSTI)

This document is a final report covering work performed under Contract No. DE-FG02-99ER82911 from the Department of Energy under a SBIR Phase II Program. Wear resistant, hard coatings can play a vital role in many engineering applications. The primary goal of this project was to develop coatings containing boron and carbon with hardness greater than 30 GPa and evaluate these coatings for machining applications. UES has developed a number of carbon and boron containing coatings with hardness in the range of 34 to 65 GPa using a combination of filtered cathodic arc and magnetron sputtering. The boron containing coatings were based on TiB2, TiBN, and TiBCN, while the carbon containing coatings ere TiC+C and hydrogen free diamond-like-carbon. Machining tests were performed with single and multilayer coated tools. The turning and milling tests were run at TechSolve Inc., under a subcontract at Ohio State University. Significant increases in tool lives were realized in end milling of H-13 die steel (8X) and titanium alloy (80%) using the TiBN coating. A multilayer TiBN/TiN performed the best in end-milling of highly abrasive Al-Si alloys. A 40% increase in life over the TiAlN benchmark coating was found. Further evaluations of these coatings with commercialization partners are currently in progress.

Bhattacharya, Rabi S.

2003-12-05T23:59:59.000Z

479

A multi-bead overlapping model for robotic wire and arc additive manufacturing (WAAM)  

Science Journals Connector (OSTI)

Abstract Wire and arc additive manufacturing (WAAM) is a promising alternative to traditional subtractive manufacturing for fabricating large aerospace components that feature high buy-to-fly ratio. Since the WAAM process builds up a part with complex geometry through the deposition of weld beads on a layer-by-layer basis, it is important to model the geometry of a single weld bead as well as the multi-bead overlapping process in order to achieve high surface quality and dimensional accuracy of the fabricated parts. This study firstly builds models for a single weld bead through various curve fitting methods. The experimental results show that both parabola and cosine functions accurately represent the bead profile. The overlapping principle is then detailed to model the geometry of multiple beads overlapping together. The tangent overlapping model (TOM) is established and the concept of the critical centre distance for stable multi-bead overlapping processes is presented. The proposed TOM is shown to provide a much better approximation to the experimental measurements when compared with the traditional flat-top overlapping model (FOM). This is critical in process planning to achieve better geometry accuracy and material efficiency in additive manufacturing.

Donghong Ding; Zengxi Pan; Dominic Cuiuri; Huijun Li

2015-01-01T23:59:59.000Z

480

Final Scientific/Technical Report "Arc Tube Coating System for Color Consistency"  

SciTech Connect (OSTI)

DOE has enabled the use of coating materials using low cost application methods on light sources to positively affect the output of those sources. The coatings and light source combinations have shown increased lumen output of LED fixtures (1.5%-2.0%), LED arrays (1.4%) and LED powered remote phosphor systems â?? Philips L-Prize lamp (0.9%). We have also demonstrated lifetime enhancements (3000 hrs vs 8000 hrs) and shifting to higher CRI (51 to 65) in metal halide high intensity discharge lamps with metal oxide coatings. The coatings on LEDs and LED products are significant as the market is moving increasingly more towards LED technology. Enhancements in LED performance are demonstrated in this work through the use of available materials and low cost application processes. EFOI used low refractive index fluoropolymers and low cost dipping processes for application of the material to surfaces related to light transmission of LEDs and LED products. Materials included Teflon AF, an amorphous fluorinated polymer and fluorinated acrylic monomers. The DOE SSL Roadmap sets goals for LED performance moving into the future. EFOIâ??s coating technology is a means to shift the performance curve for LEDs. This is not limited to one type of LED, but is relevant across LED technologies. The metal halide work included the use of sol-gel solutions resulting in silicon dioxide and titanium dioxide coatings on the quartz substrates of the metal halide arc tubes. The coatings were applied using low cost dipping processes.

Buelow, Roger; Jenson, Chris; Kazenski, Keith

2013-03-21T23:59:59.000Z

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481

Feasibility study of volumetric modulated arc therapy with constant dose rate for endometrial cancer  

SciTech Connect (OSTI)

To investigate the feasibility, efficiency, and delivery accuracy of volumetric modulated arc therapy with constant dose rate (VMAT-CDR) for whole-pelvic radiotherapy (WPRT) of endometrial cancer. The nine-field intensity-modulated radiotherapy (IMRT), VMAT with variable dose-rate (VMAT-VDR), and VMAT-CDR plans were created for 9 patients with endometrial cancer undergoing WPRT. The dose distribution of planning target volume (PTV), organs at risk (OARs), and normal tissue (NT) were compared. The monitor units (MUs) and treatment delivery time were also evaluated. For each VMAT-CDR plan, a dry run was performed to assess the dosimetric accuracy with MatriXX from IBA. Compared with IMRT, the VMAT-CDR plans delivered a slightly greater V{sub 20} of the bowel, bladder, pelvis bone, and NT, but significantly decreased the dose to the high-dose region of the rectum and pelvis bone. The MUs decreased from 1105 with IMRT to 628 with VMAT-CDR. The delivery time also decreased from 9.5 to 3.2 minutes. The average gamma pass rate was 95.6% at the 3%/3 mm criteria with MatriXX pretreatment verification for 9 patients. VMAT-CDR can achieve comparable plan quality with significant shorter delivery time and smaller number of MUs compared with IMRT for patients with endometrial cancer undergoing WPRT. It can be accurately delivered and be an alternative to IMRT on the linear accelerator without VDR capability.

Yang, Ruijie [Department of Radiation Oncology, Peking University Third Hospital, Beijing (China); Wang, Junjie, E-mail: junjiewang47@yahoo.com [Department of Radiation Oncology, Peking University Third Hospital, Beijing (China); Xu, Feng [Department of Biomedical Engineering, Peking University Third Hospital, Beijing (China); Li, Hua [Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing (China); Zhang, Xile [Department of Radiation Oncology, Peking University Third Hospital, Beijing (China)

2013-10-01T23:59:59.000Z

482

Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009)  

SciTech Connect (OSTI)

Nitrogen is difficult to remove in electric arc furnace (EAF) steelmaking, requiring the use of more energy in the oxygen steelmaking route to produce low-nitrogen steel. The objective of this work was to determine if the injection of directly reduced iron (DRI) fines into EAFs could reduce the nitrogen content by creating fine carbon monoxide bubbles that rinse nitrogen from the steel. The proposed work included physical and chemical characterization of DRI fines, pilot-scale injection into steel, and mathematical modeling to aid in scale-up of the process. Unfortunately, the pilot-scale injections were unsuccessful, but some full-scale data was obtained. Therefore, the original objectives were met, and presented in the form of recommendations to EAF steelmakers regarding: (1) The best composition and size of DRI fines to use; (2) The amount of DRI fines required to achieve a specific reduction in nitrogen content in the steel; and (3) The injection conditions. This information may be used by steelmakers in techno-economic assessments of the cost of reducing nitrogen with this technology.

Dr. Gordon A. Irons

2004-03-31T23:59:59.000Z

483

Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design  

SciTech Connect (OSTI)

A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 {mu}s. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

Kia, Kaveh Kazemi [Department of Electrical and Computer Engineering, Islamic Azad University of Bonab, Bonab (Iran, Islamic Republic of); Bonabi, Fahimeh [Department of Engineering, Islamic Azad University of Bonab, Bonab (Iran, Islamic Republic of)

2012-12-15T23:59:59.000Z

484

Design And Diagnosis Of A New Type Radio Frequency Driven In Vacuum Arc Ion Source  

SciTech Connect (OSTI)

The discharge mechanism of this source is based on the use of both RF- driven (15 MHz -300W) and vacuum arc to create discharge plasma of higher intensity. An internal antenna is used to couple the RF power to the plasma. Lower ignition voltage (50 up to 200V) and higher plasma intensity feature the characteristics of this source. The source is considered self extracted ion current and could deliver ion currents of {approx}10mA for thin beam ({phi} = 2mm.) and {approx}20 mA for broad beam ({phi} {approx} 6cm.) at {approx} 200V extraction voltage. The beam diagnostics (for thin beam) of this source are measured which include: the beam profiles, beam emittance, energy spread and distribution of the ion species in the ion beam. The increase of the anode voltage decreases the beam emittance, while the energy spread increases with the decrease of the discharge pressure. The beam emittance is found to be around 200 up to 400 mm.m.rad. and the energy spread of the ions in the ion beam is around 40 up to 80 eV. The Ar ion specie extracted from the source could reach Ar+5. The beam profiles show that the beam is more convergent with the increase of the accelerating voltage and with the use of proper capacitors between the extraction electrodes.

Zakhary, S.G. [Accelerators Dept., Nuclear Research Center, Atomic Energy Authority, P.O.Box 13759 Cairo (Egypt)

2005-03-17T23:59:59.000Z

485

Stability of very-high pressure arc discharges against perturbations of the electron temperature  

SciTech Connect (OSTI)

We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

2012-04-01T23:59:59.000Z

486

Formation of cobalt silicide from filter metal vacuum arc deposited films  

SciTech Connect (OSTI)

The thermal reaction of Co film deposited on Si (111) surfaces by a high current filter metal vacuum arc (FMEVAD) system has been studied. After deposition the films were annealed over the 400-900 C temperature range for 30 min. Rutherford Backscattering Spectrometry (RBS) was used to characterize the elemental depth distributions in the films subjected to different annealing temperatures. Ordered chemical phases were determined by glancing-incidence X-ray diffraction (GIXRD) and the morphology was determined by cross section transmission electron microscopy (TEM). The results show that the phases formed are Co2Si at 400 C, CoSi + CoO at 500 C, CoSi + CoSi2 at 600 C, and CoSi2 at (700-800 C). At 900 C, CoSi2 was formed with a mixture of cubic cobalt and probably an amorphous cobalt oxide surface layer. The interface morphology was a rough cusp-like crenellation at 600 C which became less pronounced after annealing at 800 C.

Whitlow, Harry J.; Zhang, Yanwen; Wang, Chong M.; McCready, David E.; Zhang, Tonghe; Wu, Yuguang

2006-06-01T23:59:59.000Z

487

Modern control strategies for vacuum arc remelting of segregation sensitive alloys  

SciTech Connect (OSTI)

There are several process variables which are crucial to the control of vacuum arc remelting of segregation sensitive alloys. These are: electrode gap, melt rate, cooling rate, furnace annulus, furnace atmosphere and electrode quality (i.e. cleanliness and integrity). Of these variables, active, closed loop control is usually applied only to electrode gap. Other variables are controlled by controlling furnace operational parameters to preset schedules (e.g. melting current is ramped or held constant to control melt rate in an open loop fashion), through proper maintenance and calibration of equipment (e.g. to ensure proper cooling water and gas flow rates, or to accomplish an acceptable vacuum leak rate), through proper practice of procedures, and by maintaining electrode quality control. Electrode gap control is accomplished by controlling an electrode gap indicator such as drip-short frequency (or period) to a specified set-point. This type of control, though often adequate, ignores information available from other electrode gap indicators and is susceptible to upsets. A multiple input electrode gap controller is described which uses optimal estimation techniques to address this problem.

Williamson, R.L.; Schlienger, M.E. [Sandia National Labs., Albuquerque, NM (United States); Hysinger, C.L.; Beaman, J.J. [Univ. of Texas, Austin, TX (United States)

1997-06-01T23:59:59.000Z

488

Electrochemical Testing of Gas Tungsten ARC Welded and Reduced Pressure Electron Beam Welded Alloy 22  

SciTech Connect (OSTI)

Alloy 22 (N06022) is the material selected for the fabrication of the outer shell of the nuclear waste containers for the Yucca Mountain high-level nuclear waste repository site. A key technical issue in the waste package program has been the integrity of the container weld joints. The currently selected welding process for fabricating and sealing the containers is the traditional gas tungsten arc welding (GTAW) or TIC method. An appealing faster alternative technique is reduced pressure electron beam (RPEB) welding. It was of interest to compare the corrosion properties of specimens prepared using both types of welding techniques. Standard electrochemical tests were carried on GTAW and RPEB welds as well as on base metal (non-welded) to determine their relative corrosion behavior in simulated concentrated water (SCW) at 90 C (alkaline), 1 M HCI at 60 C (acidic) and 1 M NaCl at 90 C (neutral) solutions. Results show that for all practical purposes, the three tested materials had the same electrochemical behavior in the three tested electrolytes.

S. Daniel Day; Frank M.G. Wong; Steven R. Gordon; Lana L. Wong; Raul B. Rebak

2006-05-08T23:59:59.000Z

489

Argonne's HigH THrougHpuT reseArcH LAborATory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

accelerating materials innovation accelerating materials innovation Argonne's HigH THrougHpuT reseArcH LAborATory The conventional "one-at-a-time" sequential approach for synthesizing, characterizing and evaluating new materials typically provides only incremental improvements; it is both labor- and resource-intensive as well as very expensive. T h e d is c o v e r y a n d s y n t h e s is o f n e w m a t e r ia ls a r e c r it ic a l b o t t le n e c k s in t h e s e a r c h f o r a lt e r n a t iv e e n e r g y s o u r c e s . Argonne nATionAL LAborATory's High Throughput research Laboratory accelerates the discovery and optimization of new materials, leading to "quantum jump" improvements and fast-tracked marketplace entry. Argonne's HTR provides highly automated and parallel approaches to materials development. This allows scientists to

490

Departures from local thermodynamic equilibrium in cutting arc plasmas derived from electron and gas density measurements using a two-wavelength quantitative Schlieren technique  

SciTech Connect (OSTI)

A two-wavelength quantitative Schlieren technique that allows inferring the electron and gas densities of axisymmetric arc plasmas without imposing any assumption regarding statistical equilibrium models is reported. This technique was applied to the study of local thermodynamic equilibrium (LTE) departures within the core of a 30 A high-energy density cutting arc. In order to derive the electron and heavy particle temperatures from the inferred density profiles, a generalized two-temperature Saha equation together with the plasma equation of state and the quasineutrality condition were employed. Factors such as arc fluctuations that influence the accuracy of the measurements and the validity of the assumptions used to derive the plasma species temperature were considered. Significant deviations from chemical equilibrium as well as kinetic equilibrium were found at elevated electron temperatures and gas densities toward the arc core edge. An electron temperature profile nearly constant through the arc core with a value of about 14000-15000 K, well decoupled from the heavy particle temperature of about 1500 K at the arc core edge, was inferred.

Prevosto, L.; Mancinelli, B. [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto 2600, Santa Fe (Argentina); Artana, G. [Laboratorio de Fluidodinamica, Departamento Ing. Mecanica, Facultad de Ingenieria (UBA), Paseo Colon 850, C1063ACV, Buenos Aires (Argentina); Kelly, H. [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto 2600, Santa Fe (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales (UBA), Instituto de Fisica del Plasma (CONICET), Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina)

2011-03-15T23:59:59.000Z

491

Collective dynamics underpins Rayleigh behavior in disordered polycrystalline ferroelectrics  

Science Journals Connector (OSTI)

...rho}(E1 ,E2 ) of the elementary hysterons, where E1 and E2 are lower...generators (SRS DS 345). The electric field is directed through the...calibrated to account for the Resistance-capacitance RC-behavior...Atomic-scale study of electric dipoles near charged and uncharged...

P. Bintachitt; S. Jesse; D. Damjanovic; Y. Han; I. M. Reaney; S. Trolier-McKinstry; S. V. Kalinin

2010-01-01T23:59:59.000Z

492

Cybersecurity Dynamics Shouhuai Xu  

E-Print Network [OSTI]

Cybersecurity Dynamics Shouhuai Xu Department of Computer Science, University of Texas at San Antonio ABSTRACT We explore the emerging field of Cybersecurity Dynamics, a candidate foundation for the Science of Cybersecurity. Keywords Cybersecurity dynamics, security model, security analysis 1

Xu, Shouhuai

493

Dynamic Analysis of Wind Turbine Planetary Gears Using an Extended Harmonic Balance Approach: Preprint  

SciTech Connect (OSTI)

The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.

Guo, Y.; Keller, J.; Parker, R. G.

2012-06-01T23:59:59.000Z

494

Tunable, self-powered integrated arc plasma-melter vitrification system for waste treatment and resource recovery  

DOE Patents [OSTI]

The present invention provides a relatively compact self-powered, tunable waste conversion system and apparatus which has the advantage of highly robust operation which provides complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The system provides the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or by an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In the preferred embodiment of the invention, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The preferred configuration of this embodiment of the invention utilizes two arc plasma electrodes with an elongated chamber for the molten pool such that the molten pool is capable of providing conducting paths between electrodes. The apparatus may additionally be employed with reduced or without further use of the gases generated by the conversion process. The apparatus may be employed as a self-powered or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production.

Titus, Charles H. (Newtown Square, PA); Cohn, Daniel R. (Chestnuthill, MA); Surma, Jeffrey E. (Kennewick, WA)

1998-01-01T23:59:59.000Z

495

Interplay effects between dose distribution quality and positioning accuracy in total marrow irradiation with volumetric modulated arc therapy  

SciTech Connect (OSTI)

Purpose: To evaluate the dosimetric consequences of inaccurate isocenter positioning during treatment of total marrow (lymph-node) irradiation (TMI-TMLI) using volumetric modulated arc therapy (VMAT).Methods: Four patients treated with TMI and TMLI were randomly selected from the internal database. Plans were optimized with VMAT technique. Planning target volume (PTV) included all the body bones; for TMLI, lymph nodes and spleen were considered into the target, too. Dose prescription to PTV was 12 Gy in six fractions, two times per day for TMI, and 2 Gy in single fraction for TMLI. Ten arcs on five isocenters (two arcs for isocenter) were used to cover the upper part of PTV (i.e., from cranium to middle femurs). For each plan, three series of random shifts with values between ?3 and +3 mm and three between ?5 and +5 mm were applied to the five isocenters simulating involuntary patient motion during treatment. The shifts were applied separately in the three directions: left–right (L-R), anterior–posterior (A-P), and cranial–caudal (C-C). The worst case scenario with simultaneous random shifts in all directions simultaneously was considered too. Doses were recalculated for the 96 shifted plans (24 for each patient).Results: For all shifts, differences <0.5% were found for mean doses to PTV, body, and organs at risk with volumes >100 cm{sup 3}. Maximum doses increased up to 15% for C-C shifted plans. PTV covered by the 95% isodose decreased of 2%–8% revealing target underdosage with the highest values in C-C direction.Conclusions: The correct isocenter repositioning of TMI-TMLI patients is fundamental, in particular in C-C direction, in order to avoid over- and underdosages especially in the overlap regions. For this reason, a dedicated immobilization system was developed in the authors' center to best immobilize the patient.

Mancosu, Pietro; Navarria, Piera; Reggiori, Giacomo; Tomatis, Stefano; Alongi, Filippo; Scorsetti, Marta [Department of Radiation Oncology, Humanitas Clinical and Research Center, Rozzano, Milan 20089 (Italy)] [Department of Radiation Oncology, Humanitas Clinical and Research Center, Rozzano, Milan 20089 (Italy); Castagna, Luca; Sarina, Barbara [Bone Marrow Transplantation Unit, Humanitas Clinical and Research Center, Rozzano, Milan 20089 (Italy)] [Bone Marrow Transplantation Unit, Humanitas Clinical and Research Center, Rozzano, Milan 20089 (Italy); Nicolini, Giorgia; Fogliata, Antonella; Cozzi, Luca [Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona 6500 (Switzerland)] [Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona 6500 (Switzerland)

2013-11-15T23:59:59.000Z

496

In-situ Study of Dynamic Phenomena at Metal Nanosolder Interfaces Using Aberration Corrected Scanning Transmission Electron Microcopy.  

SciTech Connect (OSTI)

Controlling metallic nanoparticle (NP) interactions plays a vital role in the development of new joining techniques (nanosolder) that bond at lower processing temperatures but remain viable at higher temperatures. The pr imary objective of this project is t o develop a fundamental understanding of the actual reaction processes, associated atomic mechanisms, and the resulting microstructure that occur during thermally - driven bond formation concerning metal - metal nano - scale (<50nm) interfaces. In this LDRD pr oject, we have studied metallic NPs interaction at the elevated temperatures by combining in - situ transmission electron microscopy (TEM ) using an aberration - corrected scanning transmission electron microscope (AC - STEM) and atomic - scale modeling such as m olecular dynamic (MD) simulations. Various metallic NPs such as Ag, Cu and Au are synthesized by chemical routines. Numerous in - situ e xperiments were carried out with focus of the research on study of Ag - Cu system. For the first time, using in - situ STEM he ating experiments , we directly observed t he formation of a 3 - dimensional (3 - D) epitaxial Cu - Ag core - shell nanoparticle during the thermal interaction of Cu and Ag NPs at elevated temperatures (150 - 300 o C). The reaction takes place at temperatures as low as 150 o C and was only observed when care was taken to circumvent the effects of electron beam irradiation during STEM imaging. Atomic - scale modeling verified that the Cu - Ag core - shell structure is energetically favored, and indicated that this phenomenon is a nano - scale effect related to the large surface - to - volume ratio of the NPs. The observation potentially can be used for developing new nanosolder technology that uses Ag shell as the %22glue%22 that stic ks the particles of Cu together. The LDRD has led to several journal publications and numerous conference presentations, and a TA. In addition, we have developed new TEM characterization techniques and phase - field modeling tools that can be used for future materials research at Sandia. Acknowledgeme nts This work was supported by the Laboratory Directed Research and Development (LDRD) program of Sandia National Laboratories. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidia ry of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

Lu, Ping

2014-10-01T23:59:59.000Z

497

De-bundling of single-wall carbon nanotubes induced by an electric field during arc discharge synthesis  

Science Journals Connector (OSTI)

Abstract As-prepared single-wall carbon nanotubes (SWCNTs) usually aggregate into bundles that have diameters of tens of nanometers, and these bundles are very difficult to separate by post-synthesis treatment for characterization and applications. In this study, we applied a constant electric field during the synthesis of \\{SWCNTs\\} by arc discharge method. As a result, ?98% of the SWCNT bundles obtained have diameters less than 10 nm, and more than 50% of the bundles are less than 3 nm in diameter, indicating a large population of isolated single or pairs of SWCNTs.

Yan-Li Zhang; Peng-Xiang Hou; Chang Liu; Hui-Ming Cheng

2014-01-01T23:59:59.000Z

498

The effect of electric current on the synthesis of single-walled carbon nanotubes by temperature controlled arc discharge  

Science Journals Connector (OSTI)

The effect of discharge current on the synthesis of single-walled carbon nanotubes (SWCNTs) was studied under controlled atmosphere at 500 °C by electric arc discharge. It was shown that the production rate of collected soot was increased but the purity of \\{SWCNTs\\} decreased with increasing discharge current. With a current of 100 A, the SWCNT was very uniform in diameter and a high purity rate of 55% was achieved, as shown by TEM and Raman spectra. Then the influence of electric force, discharge current and catalyst distribution on the formation of \\{SWCNTs\\} was also discussed.

Delong He; Tingkai Zhao; Yongning Liu; Jiewu Zhu; Guang Yu; Liling Ge

2007-01-01T23:59:59.000Z

499

Low-temperature deposited Cu electrode on chip inductors by abnormal glow discharge plasma with arc source  

Science Journals Connector (OSTI)

A new preparation method of Cu electrodes of chip inductors by an abnormal glow discharge technique with arc source at low temperature is presented. SEM observed the microstructure of the Cu electrode joints and EDX detected the interfacial diffusion between the electrodes and the ceramic matrix. The results show that the new technique can effectively suppress interfacial diffusion and Cu oxidation whereas reserve good adhesion in the electrode layer due to low deposition temperature, which can be achieved by suitable control of glow discharge voltage. Consequently, the compromise magnetic properties of the samples can be obtained.

Yaowen Wang; Hongguo Zhang; Qiang Chen; Junde Pan; Longtu Li

2002-01-01T23:59:59.000Z

500

Ion sources with arc-discharge plasma box driven by directly heated LaB{sub 6} electron emitter or cold cathode (invited)  

SciTech Connect (OSTI)

In the Budker Institute, Novosibirsk, an ion source with arc-discharge plasma box has been developed in the recent years for application in thermonuclear devices for plasma diagnostics. Several modifications of the ion source were provided with extracted current ranging from 1 to 7 A and pulse duration of up to 4 s. Initially, the arc-discharge plasma box with cold cathode was used, with which pulse duration is limited to 2 s by the cathode overheating and sputtering in local arc spots. Recently, a directly heated LaB{sub 6} electron emitter was employed instead, which has extended lifetime compared to the cold cathode. In the paper, characteristics of the beam produced with both arrangements of the plasma box are presented.

Ivanov, Alexander A.; Davydenko, Vladimir I.; Deichuli, Petr P.; Shulzhenko, Grigori I.; Stupishin, Nikolay V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)

2008-02-15T23:59:59.000Z